Methods, systems, and devices for evaluation of thermal treatment

ABSTRACT

Methods, Systems, and Devices for Evaluation of Thermal Treatment. A magnetically detectable particle and related methods, systems, and devices are provided for generating a temperature measurement for a batch or a continuous stream of material. The particle can include a first and second magnet each comprising a positive and negative pole. The particle can also include an adhesive having a release temperature and operable to attach one or both of the positive and negative poles of the first magnet proximate to the same polarity pole of the second magnet or to attach one of the positive and negative poles of the first magnet between the poles of the second magnet below the release temperature such that a first magnetic field is generated by the first and second magnet. The adhesive can also be operable to release the first and second magnets from one another above the release temperature.

RELATED APPLICATIONS

This application claims the benefit of U.S. patent application Ser. No.10/767,427, filed Jan. 28, 2004, which claims priority to U.S.Provisional Patent Application Ser. No. 60/443,298, filed Jan. 28, 2003,entitled “Methods, Systems, and Devices for Evaluation of ThermalTreatment”; the disclosure of which is incorporated herein by referencein its entirety.

Additionally, U.S. Pat. No. 6,776,523, which issued on Aug. 17, 2004,entitled “Method and System for Conservative Evaluation, Validation andMonitoring of Thermal Processing”, is incorporated herein by referencein its entirety.

GOVERNMENT INTEREST

This work was supported by the National Science Foundation (NSF)pursuant to contract number MCB 9631375. The Government has certainrights in the invention.

TECHNICAL FIELD

The subject matter disclosed herein relates generally to thermaltreatment of materials. More particularly, the subject matter disclosedherein relates to methods, systems, and devices for evaluating suchprocessing.

BACKGROUND ART

It will be appreciated by those of skill in the art that thermalprocessing of particulate-containing food products is difficult toaccomplish in an efficient but effective manner. Particulate-containingfood products are also described in the art as multi-phase foodproducts, or as multi-phase foods, in that these products includeliquids and solids.

Traditionally, thermal processing of particulate-containing foodproducts involved the placing of the product in individual cans,followed by thermal treatment of the product within the can. The processis generally effective in removing microbial contamination and inproviding a food product that is safe for consumption. However, thisprocess is labor and machinery-intensive and time-consuming. Thus, thisprocess lacks efficiency.

Continuous thermal processing generally involves the thermal processingof the food product as a stream or flow in one line while processing thecontainers or cans in which the food will be stored in another line. Thefood product is then placed in the container under appropriateconditions wherein microbes and their spores are excluded. Continuousthermal processing thus enables unlimited package size, yieldingincreased efficiencies and reduced costs to the industry and ultimatelyto the consumer. Continuous thermal processing is sometimes also calledaseptic processing the art.

In the United States, each continuous thermal process for use in thetreatment of food must be described in a document to be filed with theUnited States Food and Drug Administration (FDA) for approval before itcan be implemented in industry. Because of the problems associated withuniform treatment in the continuous thermal process, the FDA subjectsthese documents, hereinafter referred to as “FDA process filings”,“process filings” or “FDA filings”, to rigorous scrutiny.

To gain FDA approval, a process filing must demonstrate biovalidation ofthe process, among other information. As is known in the art,biovalidation refers to data showing that the process was effective inremoving contamination of the food product by microbes and their spores.To determine biovalidation, conservative residence time distributionmeasurements are required. Lengthy test runs must be performed togenerate the conservative residence time distribution measurements. Suchtest runs require a great deal of time and involve the loss of a greatdeal of the food product, as the food product that is part of the testruns have prevented the wide scale adoption in the industry ofcontinuous thermal processing of particulate-containing food products.

The current state of the art for process evaluation and validation ofcontinuous thermal processes for particulate-containing food particles,including low acid multi-phase foods, has evolved over a number of yearsthrough the joint efforts of the Center for Advanced Processing andPackaging Studies and the National Center for Food Safety andTechnology. Currently, it includes a three (3)-stage sequence. The firststage of the sequence primarily includes process modeling and simulationthat provides predicted scenarios for the efficacy of process withrespect to microbial lethality. The second stage of the sequenceincludes experimental measurements of real or simulated particleresidence times while flowing through the system for a sufficient numberof replications for each particulate product component to providestatistically acceptable (i.e. representative) data for particlevelocities to ensure that a portion of the fastest moving particles hasbeen captured and their residence times recorded for modeling purposes.The third and final stage of process evaluation and validation is abiological validation including the use of thermoresistant bacterialspore loads within simulated food particles to demonstrate theachievement of appropriate cumulative thermal time and temperature bythe implemented process—sufficient to lethally injure all bacterialspores present within the test particles.

Procedures disclosed in the art attempt to implement these stages byusing various methods of particle residence time measurement. Forexample, U.S. Pat. No. 5,261,282 to Grabowski et al. discloses the useof implanted radio frequency transponders to identify simulatedparticles passing through a continuous process system. U.S. Pat. No.5,741,979 to Arndt et al. discloses the use of dipole antenna markerimplants in the particles and microwave transducer detectors to measureparticle residence times.

Segner et al., “Biological Evaluation of a Heat Transfer Simulation forSterilizing Low-Acid Large Particulate Foods for Thermal Packaging”,Journal of Food Processing and Preservation, 13:257-274, (1989); Tucker.G. S. and Withers, P. M., “Determination of Residence Time Distributionof Food Particles in Viscous Food Carrier Fluids using Hall effectsensors”, Technical Memorandum 667, Campden Food and Drink ResearchAssociation (CFDRA), Campden, Glos., U.K. (1992); “Case Study forCondensed Cream of Potato Soup”, Aseptic Processing of Multi-phase FoodsWorkshop, Nov. 14-15, 1995 and Mar. 12-13, 1996 (published 1997); U.S.Pat. No. 5,750,907 to Botos et al.; U.S. Pat. No. 5,739,437 to Sizer etal.; and U.S. Pat. No. 5,876,771 to Sizer et al. all disclose the use ofpermanent magnets for implants (single tag type) and a variety ofmagnetic field sensors to detect and record their passage throughseveral system segments and locations.

The necessity for measurements of particle residence time and subsequentbiological process validation using bacterial spores is a result of thecurrent inability to measure temperature in the “cold spot” (the slowestheating point within a particle) of the fastest moving, slowest heatingparticle present in the continuously thermally processed multiphaseproduct. Several techniques have been proposed in the art for thispurpose and can be grouped into two groups: techniques implementingcross sectional imaging/tomography of the entire flow profile andtechniques implementing thermosensitive implants in specific particlelocations.

Magnetic resonance imaging thermometry, such as that disclosed byLitchfield et al., “Mapping Food Temperature with Magnetic ResonanceImaging”, National Research Initiative Competitive Grant Program,Cooperative State Research, Education, and Extension Service, UnitedStates Department of Agriculture (March 1998), is a non-obstructing andnon-contact method, but is not rapid enough to provide in-line real timemeasurements. It took eight seconds to image a single 64×64cross-sectional temperature map. During this time a considerablequantity of product would pass the detector unmonitored. It is alsoextremely complex and cumbersome for these types of measurements,requiring complicated technology, highly trained personnel, andspecialized power and power conditioning. Due to all these factors, thenumber of windows/cross sections that can be observed and monitoredwithin the process equipment is very limited, i.e. the detection of theinitial location where the lethal thermal treatment temperature isachieved cannot be determined for all possible cases. The applicabilityof detection through stainless steel equipment walls without specialports or windows is unclear.

Similar shortcomings are evident with the other tomographic/crosssectional imaging techniques implementing ultrasonic tomography andtomographic reconstruction, such as that disclosed in U.S. Pat. No.5,181,778 to Bellter. Particularly, due to system complexity, the numberof observed cross sections is limited. Another problem with the Bellersystem is the potential for misidentifying the thermal profilesoccurring within or outside of the particle. For example, Bellerdiscloses that the curve of the speed of sound versus temperature forpotatoes approximately paralleled that of water above about 110° C. Thisindicates a potential material and location misidentification of fluidvs. solid temperatures. Additionally, standardization and calibrationcurves must be generated for each and every potential product component,necessitating a very laborious and lengthy measurement and calibrationprocedure prior to implementation. The applicability of detectionthrough stainless-steel equipment walls without special ports or windowsis also unclear.

Methodologies that implement thermosensitive implants include the localmagnetic temperature measurement approach disclosed in U.S. Pat. No.5,722,317 to Ghiron et al. Ghiron et al. disclose the use of sphericalparamagnetic particles for implants and detector coils around the pipesfor sensors. The approach then implements the correlation between thefalling magnetic field strength and temperature increase to calculatethe implant temperature from the signals of three sensor coils. However,the negative correlation between the measured magnetic field and theincreasing temperature employed by the Ghiron et al. approach can causea non-conservative temperature estimation, i.e. the resultingcalculation can indicate a higher temperature than is actually presentin the implant. This is due to the fact that magnetic field reductioncan be caused by a variety of factors other than temperature increase inthe implant, such as the particle or the detection system being out ofcalibration, reduction of sensitivity of the detection system, andobstruction of detection by other materials such as other present foodparticles. The complexity of the system disclosed by Ghiron et al. alsolimits the number of observation points as well as the applicability athigh-temperature, short time processing levels.

The Campden and Chorleywood Food Research Association in Great Britainreports on the use of a Temperature Responsive Inductance Particle(TRIP) sensor, which can be placed in the food product. The timetemperature history of the sensor is purportedly monitored/logged inreal time outside the processing equipment/environments. See ResearchSummary Sheets, 1997-68, “TRIP—A New Approach to the Measurement of Timeand Temperature in Food Processing Systems”. Most of the details of thismethodology are not publicly available. However, one of the accessible,limited reports indicates that the sensor size is about 5 mm indiameter. This size precludes its use to measure the “cold spot”temperatures in aseptically processed particles. Additionally, nodisclosure is made with respect to capability for the monitoring throughstainless steel equipment and current applicability to continuousprocesses.

One common shortcoming of all available systems is the inability toprovide a detectable particle that closely mimics the behavior of anactual food particle. This is a serious disadvantage due to the factthat the detectable particle will not provide an accurate temperaturemeasurement of a food particle's “cold spot” temperature. This canresult in a non-conservative measurement and therefore non-conservativeprocess evaluation. Thus, what is needed is a method, system, and devicethat can provide conservative temperature measurements in a continuousthermal processing of particulate-containing food products, batch, orother applications.

SUMMARY

According to one embodiment, a magnetically detectable particle isdisclosed for generating a temperature measurement for a batch or acontinuous stream of material. The particle can include a first andsecond magnet each comprising a positive and negative pole. The particlecan also include an adhesive having a release temperature and operableto attach one or both of the positive and negative poles of the firstmagnet proximate to the same polarity pole of the second magnet or toattach one of the positive and negative poles of the first magnetbetween the poles of the second magnet below the release temperaturesuch that a first magnetic field is generated by the first and secondmagnet. The adhesive can also be operable to release the first andsecond magnets from one another above the release temperature. The firstand second magnets can move with respect to one another when theadhesive releases the first and second magnets such that one of thepositive and negative poles of the first magnet moves toward theopposing polarity pole of the second magnet for generating a secondmagnetic field different than the first magnetic field to indicate atemperature measurement for the batch or continuous stream.

According to a second embodiment, a method is disclosed for generating atemperature measurement for a batch or a continuous stream of material.The method can include a step for providing a magnetically detectableparticle. The particle can include a first and second magnet eachcomprising a positive and negative pole. The particle can also includean adhesive having a release temperature and operable to attach one orboth of the positive and negative poles of the first magnet proximate tothe same polarity pole of the second magnet or to attach one of thepositive and negative poles of the first magnet between the poles of thesecond magnet below the release temperature such that a first magneticfield is generated by the first and second magnet. The adhesive can alsobe operable to release the first and second magnets from one anotherabove the release temperature. The first and second magnets can movewith respect to one another when the adhesive releases the first andsecond magnets such that one of the positive and negative poles of thefirst magnet moves toward the opposing polarity pole of the secondmagnet for generating a second magnetic field different than the firstmagnetic field to indicate a temperature measurement for the batch orcontinuous stream. The method can also include a step for inserting thedetectable particle into the batch or continuous stream. Further, themethod can include a step for detecting a change in magnetic fieldstrength of the detectable particle to thereby generate a temperaturemeasurement for the batch or continuous stream.

According to a third embodiment, a system is disclosed for generating atemperature measurement for a batch or a continuous stream of material.The system can include a magnetically detectable particle. The particlecan include a first and second magnet each comprising a positive andnegative pole. The particle can also include an adhesive having arelease temperature and operable to attach one or both of the positiveand negative poles of the first magnet proximate to the same polaritypole of the second magnet or to attach one of the positive and negativepoles of the first magnet between the poles of the second magnet belowthe release temperature such that a first magnetic field is generated bythe first and second magnet. The adhesive can also be operable torelease the first and second magnets from one another above the releasetemperature. The first and second magnets can move with respect to oneanother when the adhesive releases the first and second magnets suchthat one of the positive and negative poles of the first magnet movestoward the opposing polarity pole of the second magnet for generating asecond magnetic field different than the first magnetic field toindicate a temperature measurement for the batch or continuous stream.The system can also include a detector for detecting a change from thefirst magnetic field to the second magnetic field to thereby generate atemperature measurement for the batch or continuous stream.

According to a fourth embodiment, a method is disclosed for generating atemperature measurement for a batch or a continuous stream of material.The method can include a step for providing a plurality of magneticallydetectable particles. Each particle can include a first and secondmagnet each comprising a positive and negative pole. Each particle canalso include an adhesive having a release temperature and operable toattach one of the positive and negative poles of the first magnet to thesame polarity pole of the second magnet or between the poles of thesecond magnet below the release temperature such that a first magneticfield is generated by the first and second magnet, and operable torelease the first and second magnets from one another above the releasetemperature. The first and second magnets can move with respect to oneanother when the adhesive releases the first and second magnets suchthat one of the positive and negative poles of the first magnet movestoward the opposing polarity pole of the second magnet for generating asecond magnetic field different than the first magnetic field toindicate a temperature measurement for the batch or continuous stream.The method can also include a step for inserting the detectableparticles into the batch or continuous stream. Further, the method caninclude a step for detecting a change in magnetic field strength fromeach of the detectable particles to thereby generate a temperaturemeasurement for the batch or continuous stream.

According to a fifth embodiment, a magnetically detectable particle isdisclosed for generating a temperature measurement for a batch or acontinuous stream of material. The particle can include a first, second,and third magnet each comprising a positive and negative pole. The firstadhesive can have a first release temperature and operable to attach thenegative pole of the first magnet to the negative polarity pole of thesecond magnet below the first release temperature, and operable torelease the first and second magnets from one another above the firstrelease temperature. The second adhesive can have a second releasetemperature and operable to attach the positive pole of the third magnetto the positive pole of the second magnet below the first releasetemperature, and operable to release the second and third magnets fromone another above the first release temperature. A first magnetic fieldcan be generated by the first, second, and third magnets when the firstmagnet and third magnets are attached to the second magnet. The firstand second magnets can move with respect to one another when the firstadhesive releases the first and second magnets such that the positivepole of the first magnet moves toward the negative pole of the secondmagnet for generating a second magnetic field different than the firstmagnetic field to indicate a first temperature measurement for the batchor continuous stream. The second and third magnets can move with respectto one another when the second adhesive releases the second and thirdmagnets such that the negative pole of the third magnet moves toward thepositive pole of the second magnet for generating a third magnetic fielddifferent than the first magnetic field to indicate a second temperaturemeasurement for the batch or continuous stream.

According to a sixth embodiment, a magnetically detectable particle isdisclosed for generating an environmental condition measurement. Theparticle can include a first and second magnet each comprising apositive and negative pole. The particle can also include an adhesiveoperable to attach one of the positive and negative poles of the firstmagnet to the same polarity pole of the second magnet or between thepoles of the second magnet when a predetermined environmental conditionis not detected such that a first magnetic field is generated by thefirst and second magnet. The adhesive can also be operable to releasethe first and second magnets from one another when the predeterminedenvironmental condition is detected. The first and second magnets canmove with respect to one another when the adhesive releases the firstand second magnets such that one of the positive and negative poles ofthe first magnet moves toward the opposing polarity pole of the secondmagnet for generating a second magnetic field different than the firstmagnetic field to indicate a temperature measurement for the batch orcontinuous stream.

According to a seventh embodiment, a method is disclosed for generatingan environmental condition measurement in an environment. The method caninclude a step for providing a magnetically detectable particle. Theparticle can include a first and second magnet each comprising apositive and negative pole. The particle can also include an adhesiveoperable to attach one of the positive and negative poles of the firstmagnet to the same polarity pole of the second magnet when apredetermined environmental condition is not detected such that a firstmagnetic field is, generated by the first and second magnet. Theadhesive can also be operable to release the first and second magnetsfrom one another when the predetermined environmental condition isdetected. The first and second magnets can move with respect to oneanother when the adhesive releases the first and second magnets suchthat one of the positive and negative poles of the first magnet movestoward the opposing polarity pole of the second magnet for generating asecond magnetic field different than the first magnetic field toindicate a temperature measurement for the batch or continuous stream.The method can also include a step for inserting the detectable particleinto the environment. Further, the method can include a step fordetecting a change in magnetic field strength of the detectable particleto thereby generate a temperature measurement for the environment.

According to an eighth embodiment, a system is disclosed for generatingan environmental condition measurement for an environment. The systemcan include a magnetically detectable particle. The particle can includea first and second magnet each comprising a positive and negative pole.The particle can also include an adhesive operable to attach one of thepositive and negative poles of the first magnet to the same polaritypole of the second magnet when a predetermined environmental conditionis not detected such that a first magnetic field is generated by thefirst and second magnet. The adhesive can also be operable to releasethe first and second magnets from one another when the predeterminedenvironmental condition is detected. The first and second magnets canmove with respect to one another when the adhesive releases the firstand second magnets such that one of the positive and negative poles ofthe first magnet moves toward the opposing polarity pole of the secondmagnet for generating a second magnetic field different than the firstmagnetic field to indicate a temperature measurement for the batch orcontinuous stream. The system can also include a detector for detectinga change from the first magnetic field to the second magnetic field tothereby generate an environmental condition measurement for theenvironment.

According to a ninth embodiment, a magnetically detectable particle isdisclosed for generating a temperature measurement for a batch or acontinuous stream of material. The particle can include a plurality ofsets of first and second magnets, each of the first and second magnetscomprising a positive and negative pole. The particle can also include aplurality of adhesives each corresponding to one of the sets of firstand second magnets, the adhesives each having a release temperature andeach adhesive operable to attach one of the positive and negative polesof the corresponding first magnet between the positive and negativepoles of the corresponding second magnet below the release temperaturesuch that a first magnetic field is generated by the corresponding firstand second magnet. Each adhesive can also be operable to release thefirst and second magnets from one another above the release temperature.The corresponding first and second magnets can move with respect to oneanother when the adhesive releases the corresponding first and secondmagnets such that one of the positive and negative poles of thecorresponding first magnet moves toward the opposing polarity pole ofthe corresponding second magnet for generating a second magnetic fielddifferent than the first magnetic field to indicate a temperaturemeasurement for the batch or continuous stream.

According to a tenth embodiment, a device is disclosed for generating atemperature measurement for a batch or continuous stream of material.The device can include a detectable particle comprising a signal thatchanges at a predetermined temperature. The device can also include acarrier particle comprising an interior cavity holding the detectableparticle. The carrier particle can have a conservative behaviorcharacteristic matching a target particle, wherein the thermalprotection provided by the carrier particle to the interior cavity isgreater than or equivalent to conservative thermal behavior of a targetparticle at its cold spot under similar heating conditions.

According to an eleventh embodiment, a method is disclosed forgenerating a temperature measurement for a batch or a continuous streamof material. The method can include a step for providing a deviceincluding a detectable particle comprising a signal that changes at apredetermined temperature. The device can also include a carrierparticle comprising an interior cavity holding the detectable particle.The carrier particle comprises a conservative behavior characteristicmatching a target particle, wherein the thermal protection provided bythe carrier particle to the interior cavity is greater than orequivalent to conservative behavior characteristics of a target particleto the cold spot under similar heating conditions. The method can alsoinclude a step for inserting the device into the batch or continuousstream. Further, the method can include a step for detecting a signalchange of the device to thereby generate a temperature measurement forthe batch or continuous stream.

According to a twelfth embodiment, a method is disclosed for providing acarrier particle with conservative behavior characteristics in a batchor continuous stream of material. The method can include a step fordetermining conservative behavior characteristics of a target particlefound in a batch or continuous stream of material. The method can alsoinclude a step for determining material and dimensions for a carrierparticle design that substantially correspond to one or moreconservative behavior characteristics of the target particle.

According to a thirteenth embodiment, a method is disclosed forproviding a carrier particle with conservative behavior characteristicsin a batch or continuous stream of material. The method can include astep for simulating thermal treatment of a target particle until apredetermined lethality is accumulated. The method can also include astep for simulating a carrier particle under the same thermal treatmentsimulated in the first step. The carrier particle can have an interiorcavity and a wall. Further, the method can include a step fordetermining a conservative thickness for the wall of the carrierparticle such that the interior cavity of the carrier particle canreceive the same predetermined lethality as the target particle underthe thermal treatment simulated in the first step.

According to a fourteenth embodiment, a system is disclosed for aidingthe design of a carrier particle with conservative behaviorcharacteristics in a batch or continuous stream of material. The systemcan include a memory comprising conservative behavior characteristics ofa target particle used in a batch or continuous stream of material. Thesystem can also include a spatial simulation engine operable to simulatematerial and dimensions of a carrier particle design for matching theconservative behavior characteristics of the target particle.

According to a fifteenth embodiment, computer-readable medium isdisclosed having stored thereon instructions for aiding the design of acarrier particle with conservative behavior characteristics in a batchor continuous stream of material. The computer-readable medium caninclude instructions for determining conservative behaviorcharacteristics of a target particle used in a batch or continuousstream of material. The computer-readable medium can also includeinstructions for determining material and dimensions for a carrierparticle design about matching the conservative behavior characteristicsof the target particle.

According to a sixteenth embodiment, a computer-readable medium isdisclosed having stored thereon instructions for aiding the design of acarrier particle with conservative behavior characteristics in a batchor continuous stream of material. The computer-readable medium caninclude instructions for simulating thermal treatment of a targetparticle until a predetermined lethality is accumulated. Thecomputer-readable medium can also include instructions for simulating acarrier particle under the same thermal treatment simulated in the firststep. The carrier particle can have an interior cavity and a wall.Further, the computer-readable medium can include instructions fordetermining a conservative thickness for the wall of the carrierparticle such that the interior cavity of the carrier particle canreceive the same predetermined lethality as the target particle underthe thermal treatment simulated in the first step.

Some of the objects of the invention having been stated hereinabove, andwhich are addressed in whole or in part by the present invention, otherobjects will become evident as the description proceeds when taken inconnection with the accompanying drawings as best described hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the subject matter will now be explained withreference to the accompanying drawings, of which:

FIG. 1 is a schematic diagram of combining a first and second magnet atopposing magnetic poles to achieve a combined magnet;

FIG. 2 is a schematic diagram of the result of combining a first andsecond magnet at similar magnetic poles to achieve a combined magnet;

FIGS. 3A, 3C, and 3E are schematic diagrams of a magnetically detectableparticle in a state below a predetermined conservative temperature;

FIG. 3B, 3D, and 3F are schematic diagrams of the magneticallydetectable particle of FIG. 3A, 3C, and 3F, respectively, in a stateabove a predetermined conservative temperature;

FIGS. 3G-3I are schematic diagrams of the assembly and operation of oneembodiment of a magnetically detectable particle comprising multiplemagnets;

FIGS. 3J-3L are schematic diagrams of carrier particles comprisingmultiple detectable particles;

FIG. 4 is a schematic diagram of the principle of forced coupling andfixing similar magnets;

FIG. 5A is a schematic diagram of another embodiment of a magneticallydetectable particle in a state below a predetermined conservativetemperature;

FIG. 5B is a schematic diagram of the magnetically detectable particleof FIG. 5A in a state above the predetermined conservative temperature;

FIG. 6A is a schematic diagram of another embodiment of a magneticallydetectable particle in a state below a predetermined conservativetemperature;

FIG. 6B is a schematic diagram of the magnetically detectable particleof FIG. 6A in a state above the predetermined conservative temperature;

FIG. 6C is a schematic diagram of another embodiment of a magneticallydetectable particle in a state below a predetermined conservativetemperature;

FIGS. 6D and 6E are schematic diagrams of the magnetically detectableparticle of FIG. 6C in a state above the predetermined conservativetemperature;

FIG. 6F is a schematic diagram of a carrier particle comprising adetectable particle comprising more than two magnets (e.g. threemagnets), all assembled using the same adhesive;

FIG. 7A is a schematic diagram of another embodiment of a magneticallydetectable particle in a state below a first predetermined conservativetemperature;

FIG. 7B is a schematic diagram of the magnetically detectable particleof FIG. 7A in a state above the first predetermined conservativetemperature and below a second predetermined temperature;

FIG. 7C is a schematic diagram of the magnetically detectable particleof FIGS. 7A and 7B in a state above the first and second predeterminedtemperatures;

FIGS. 7D-7G are schematic diagrams of carrier particles comprisingmultiple detectable particles;

FIG. 8 illustrates a schematic diagram of attaching a first and secondmagnet via a metal alloy and thermo-resistant adhesive;

FIG. 9 is an experimental system for use in demonstrating magneticallydetectable particles, carrier particles, and related devices;

FIG. 10 is a perspective view of a simulated particle containing acoupled magnet sensor/detector;

FIG. 11 is a perspective view of another simulated particle including athermocouple lead having contact with a magnet assembly;

FIG. 12 is a still image of a simulated particle with the experimentalsystem of FIG. 9;

FIG. 13 is a perspective view of a data acquisition system including adisplay for presenting acquired temperature information and magnetcfield strength data;

FIGS. 14A-14D are different perspective views of a triple magnetassembly being assembled in a simulated particle;

FIG. 15 is still image of a magnet pair with a U.S. penny for providinga size scale perspective;

FIG. 16 is a graph of magnetic field strength from two naturally alignedidentical magnets with no heating;

FIG. 17 is a graph of magnetic field strength from two aligned andattached magnets with no heating;

FIG. 18 is a graph of magnetic field strength from two aligned andattached with heating;

FIG. 19 is a graph showing applied temperature versus magnetic fieldstrength;

FIG. 20 is a graph showing applied temperature versus magnetic fieldstrength;

FIG. 21 is a graph showing applied temperature versus magnetic fieldstrength;

FIGS. 22 is a graph showing applied temperature versus magnetic fieldstrength;

FIGS. 23-27 are different graphs of experimental results obtained bytesting the device shown in FIGS. 3A and 3B with an adhesive comprisinga metal alloy with a melting point of 138.3° C.;

FIGS. 28-30 are different graphs of experimental results obtained bytesting the device shown in FIGS. 3A and 3B with an adhesive comprisinga metal alloy with a melting point of 123.9° C.;

FIG. 31 is a graph of magnetic field strength versus temperatureobtained using the assembly shown in FIGS. 5A and 5B was tested usingthe experimental system shown in FIG. 9;

FIG. 32 is a graph of magnetic field strength versus temperatureobtained using the assembly shown in FIGS. 6A and 6B was tested usingthe experimental system shown in FIG. 9;

FIG. 33 is a graph of magnetic field strength versus temperatureobtained using the assembly shown in FIG. 7 was tested using theexperimental system shown in FIG. 9;

FIG. 34 is a schematic diagram of an exemplary system for conservativeevaluation, validation, and monitoring of thermal processing;

FIG. 35 is a schematic diagram of a computer system that can facilitatethe design of a carrier particle about matching the conservativebehavior characteristics of a selected target particle;

FIG. 36 is a flow chart that illustrates a process for providing acarrier particle having materials and dimensions to providecharacteristics for the carrier particle that about match theconservative behavior characteristics of a selected target particle;

FIG. 37 is an illustration of two screen displays show resultsindicating that using an overly conservative carrier particle design canresult in a potato food particle receiving cumulative lethality in itscold spot up to two orders of magnitude greater than required forcommercial sterility;

FIG. 38 is an illustration of two screen displays that show othersimulations applied to a carrier particle design and ⅜ inch potato foodparticle, respectively, under similar conditions;

FIG. 39 is an illustration of two screen displays that show othersimulations applied to a carrier particle design and a 0.5 inch×0.5inch, cylindrical, potato food particle, respectively, under similarconditions;

FIG. 40 is an illustration of two screen displays that show othersimulations applied to a carrier particle design and a ⅜ inch×⅜ inch,cylindrical, potato food particle, respectively, under similarconditions;

FIG. 41 is a schematic diagram of a 0.5 inch, cubic particle design forsimulation by a spatial simulation engine;

FIG. 42 is an illustration of a screen display showing exemplarysimulation results for cubic particle design of FIG. 41;

FIG. 43 is schematic diagram showing a grid relating to FIG. 42 of theresult of heating each of its cubes in the thermal processingsimulation;

FIG. 44 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch TPX carrier particle design;

FIG. 45 is a schematic diagram showing a grid of the result of heatingthe TPX carrier particle design of FIG. 44 in the same thermalprocessing simulation of the target particle;

FIG. 46 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch nylon carrier particle design;

FIG. 47 is a schematic diagram showing a grid of the result of heatingthe nylon carrier particle design of FIG. 46 in the same thermalprocessing simulation of the target particle;

FIG. 48 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch TEFLON™ carrier particle design;

FIG. 49 is a schematic diagram showing a grid of the result of heatingthe TEFLON™ carrier particle design of FIG. 44 in the same thermalprocessing simulation of the target particle;

FIG. 50 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch polypropylene carrier particle design;

FIG. 51 is a schematic diagram showing a grid of the result of heatingthe polypropylene carrier particle design of FIG. 50 in the same thermalprocessing simulation of the target particle;

FIG. 52 is a schematic diagram of a ⅜ inch cubic particle design forsimulation by spatial simulation engine;

FIG. 53 is an illustration of a screen display showing exemplarysimulation results for the cubic particle design shown in FIG. 52;

FIG. 54 is a schematic diagram showing a grid of the result of heatingeach of cubes in the thermal processing simulation;

FIG. 55 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch TPX carrier particle design;

FIG. 56 is a schematic diagram showing a grid of the result of heatingeach of cubes in the thermal processing simulation;

FIG. 57 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch nylon carrier particle design;

FIG. 58 is a schematic diagram showing a grid of the result of heatingthe nylon carrier particle design of FIG. 57 in the same thermalprocessing simulation of the target particle;

FIG. 59 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch TEFLON™ carrier particle design;

FIG. 60 is a schematic diagram showing a grid of the result of heatingthe TEFLON™ carrier particle design of FIG. 59 in the same thermalprocessing simulation of the target particle;

FIG. 61 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch polypropylene carrier particle design;

FIG. 62 is a schematic diagram showing a grid of the result of heatingthe polypropylene carrier particle design of FIG. 61 in the same thermalprocessing simulation of the target particle;

FIG. 63 is a schematic diagram of a cylindrical particle design forsimulation by spatial simulation engine;

FIG. 64 is an illustration of a screen display showing exemplarysimulation results for the cylindrical particle design shown in FIG. 63;

FIG. 65 is a schematic diagram showing a plurality of circular portionsand the result of heating each of circular portions in the thermalprocessing simulation;

FIG. 66 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch, TPX carrier particle design;

FIG. 67 is a schematic diagram showing a plurality of circular portionsof the result of heating the TPX carrier particle design of FIG. 66 inthe same thermal processing simulation of the target particle;

FIG. 68 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch nylon carrier particle design;

FIG. 69 is a schematic diagram showing a plurality of circular portionsof the result of heating the nylon carrier particle design of FIG. 46 inthe same thermal processing simulation of the target particle;

FIG. 70 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch TEFLON™ carrier particle design;

FIG. 71 is a schematic diagram showing a plurality of circular portionsof the result of heating the TEFLON™ carrier particle design of FIG. 66in the same thermal processing simulation of the target particle;

FIG. 72 is an illustration of a screen display showing exemplarysimulation results for a 0.5 inch polypropylene carrier particle design;

FIG. 73 is a schematic diagram showing a plurality of circular portionsof the result of heating the polypropylene carrier particle design ofFIG. 72 in the same thermal processing simulation of the targetparticle;

FIG. 74 is a schematic diagram of a cylindrical particle design forsimulation by a spatial simulation engine;

FIG. 75 is an illustration of a screen display showing exemplarysimulation results for the cylindrical particle design shown in FIG. 74;

FIG. 76 is a schematic diagram showing a plurality of circular portionsof the result of heating each of circular portions in the thermalprocessing simulation;

FIG. 77 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch TPX carrier particle design;

FIG. 78 is a schematic diagram showing a plurality of circular portionsof the result of heating the TPX carrier particle design of FIG. 77 inthe same thermal processing simulation of the target particle;

FIG. 79 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch nylon carrier particle design;

FIG. 80 is a schematic diagram showing a plurality of circular portionsof the result of heating the nylon carrier particle design of FIG. 57 inthe same thermal processing simulation of the target particle;

FIG. 81 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch TEFLON™ carrier particle design;

FIG. 82 is a schematic diagram showing a grid of the result of heatingthe TEFLON™ carrier particle design of FIG. 81 in the same thermalprocessing simulation of the target particle;

FIG. 83 is an illustration of a screen display showing exemplarysimulation results for a ⅜ inch polypropylene carrier particle design;

FIG. 84 is a schematic diagram showing a grid of the result of heatingthe polypropylene carrier particle design of FIG. 83 in the same thermalprocessing simulation of the target particle;

FIG. 85 is a flow chart that illustrates a process for designing acarrier particle having characteristics about matching the conservativebehavior characteristics of a selected target particle;

FIG. 86 is an illustration of a screen display of an applicationproviding a dropdown menu for selecting a target food particle forsimulation;

FIG. 87 is an illustration of a screen display of an applicationproviding a menu for receiving operator input for designing a carrierparticle;

FIGS. 88A and 88B are illustrations of screen displays of an applicationproviding the results of the information entered in the screen displayof FIG. 87;

FIGS. 89A and 89B are illustrations of screen displays of an applicationproviding exemplary results of simulation information entered by anoperator; and

FIGS. 90A and 90B are illustrations of screen displays of an applicationproviding exemplary results of other simulation information entered byan operator.

DETAILED DESCRIPTION

Temperature measurements for the continuously flowing particles in athermal multi-phase processing system need to be performed in such a waythat will not obstruct or impede the stream of continuously movingproduct within the system. If the stream of the observed targets needsto be impeded, slowed down or stopped to implement the measurement, thiswill generally result in non-conservative measurement and thereforenon-conservative process evaluation.

Temperature measurements therefore need to be performed usingnon-obstructing, non-contact measurement techniques and using asufficiently rapid response and detection to enable recording of thetemperature in full stream and in real time. The detection system shouldalso preferably be functional the geometry or material structures.Finally, embodiment of a temperature measurement method and systemshould measure temperature in the “cold spot” of the fastest moving,slowest heating particle present in the continuously thermally processedmulti-phase product.

Particularly, methods and systems are provided that can conservativelygenerate temperature measurements in batch and in continuous thermalprocessing of particulate-containing food products, among otherapplications. In some embodiments, the methods and systems describedherein can implement a large number of inexpensive, robust, thermallystable sensors adjusted to cover and monitor the entire length of aprocess hold tube and reliably ensure the detection of the time andplace of target temperature achievement, regardless of its locationalong the tube length. Thus, a conservative temperature measurement isassured for all processed products and particle types withoutcomplicated system modifications. Optionally, the number (and thussystem sensitivity) and density of sensors can be increased at specificpath areas of interest to enable more precise location and measurement.

While treatment of the methods and systems described herein can beapplied to food products, other representative applications includeother types of thermal treatment, such as enzymatic inactivation,thermal inactivation or destruction of other harmful components(viruses, toxins, carcinogens, mutagens, and contaminants); thermal orcatalytic process enhancement; and thermal treatments of variousmaterials required to achieve either a minimum temperature or a minimumtime-temperature process combination. The subject matter disclosedherein thus pertains to temperature measurement methods and systems thatprovide conservative measurement with respect to a variety of particles,such as-real food particles with no characteristic compensation oradjustment; non-food biomaterial particles; and organic and inorganicthermally treated particles, whether natural or fabricated.

Conservative temperature measurement is defined herein as a measurementthat provides temperature detection only when a selected minimumtemperature is reached by the observed target. Conservative temperaturemeasurement is of particular importance in thermal microbicidaltreatments such as pasteurization and sterilization since it provides atool to assure that the minimal required cumulative microbicidal thermalprocess has been received by the observed target. Correspondingly, then,a conservative temperature evaluation method as referred to herein is amethod that assures detection and recording of all temperaturesexceeding a preselected or predetermined temperature level.

Following long-standing patent law convention, the terms “a” and “an”mean “one or more” when used in this application, including the claims.

I. Methods and Systems Temperature Level Detection and Recording

Methods and systems are provided for generating a temperaturemeasurement for a batch or a continuous stream of material, particularlyfood materials. Additionally, a magnetically detectable particle isdisclosed that can be applied to these methods and systems. According toone embodiment, the detectable particle comprises a first and secondmagnet having a positive and negative pole. One of the positive andnegative poles of the first magnet can be attached to the same polaritypositive or negative pole of the second magnet. This arrangement of themagnets can generate a first magnetic field and can have the effect ofreducing or canceling the magnetic field strength of the first andsecond magnet.

The magnetically detectable particle can also comprise an adhesivehaving a release temperature and operable to attach the first and secondmagnets together above the release temperature and release the first andsecond magnets from one another above the release temperature. When theadhesive releases the first and second magnets, the first and secondmagnets can move with respect to one another such that one of thepositive and negative poles of the first magnet moves toward theopposite polarity positive or negative pole of the second magnet. Thisarrangement of the magnets can generate a detectable change in magneticfield strength to indicate a temperature measurement for the batch orcontinuous stream.

Generally, by the term “detectable particle” or “magnetically detectableparticle”, it is meant a particle that includes an implant that isdetectable by magnetic field sensors that can be used in the methods andsystems described herein. According to one embodiment, a system caninclude a magnetically detectable particle as described herein and adetector for detecting a change from a first magnetic field to a secondmagnetic field to thereby generate a temperature measurement for thebatch or continuous stream. According to another embodiment, the methodcan include providing the magnetically detectable particle describedherein; inserting the detectable particle into a batch or continuousstream; and detecting a change in magnetic field strength of thedetectable particle to thereby generate a temperature measurement forthe batch or continuous stream. The magnetic field signal can bedetected by external non-contacting magnetic sensors, and can beindicated in a number of ways, including by a closing of relays, bylight indicators, by alarms, and other suitable indicators known tothose of skill in the art. Further, the methods and systems describedherein can be used for the monitoring and recording of achievedtemperature levels and the additional data (e.g., time required forachievement of temperature associated with the temperature event). Themethods and systems described herein can be used for remote, non-contactdetection (such as, for example, during a flow of multi-phase materialscontaining solids within sealed vessels). Specifically, the generatedsignals can be detected through stainless steel walls or enclosures ofstandard sanitary processing equipment for, e.g., foodstuffs andbiomaterials. Alternatively, the methods and systems can be applied tothe detection of overheating reactors, industrial heaters and otherequipment (i.e., critical temperature detection in automotiveapplications).

The methods and systems described herein can be used to detect thatpredetermined temperature levels have been reached in a wide variety ofobjects and materials. According to one embodiment, the objects andmaterials can be simulated and real food particles. The detectableparticle can be inserted within, attached to, or otherwise integratedinto a simulated or real food particle. The simulated food particles canbe adjusted or designed to provide conservative flow and heatingbehavior when compared to other food particles present in, e.g., acontinuously, thermally-processed multiphase food product. In someembodiments, the implant's magnetic field strength can be monitored viaa series of non-contacting giant magneto resistive (GMR) magnetic fieldsensors. Detection of a change in magnetic signal can indicate a pointin the system (e.g., location and time-of-flight) needed for acustom-designed conservative particle to achieve a pre-set temperaturein the center of the particle or at the implant location. This detectioncan assure that each and every other real food particle has achieved atleast the preset temperature at or prior to the detection location.Thus, the methods and systems described herein can facilitate aconservative time-temperature detection system for continuous flowthermal processing of multiphase food products.

In addition to monitoring flows and thermal histories of continuouslythermally processed multiphase foods, the methods and systems describedherein can be used for the detection of any increase in temperatureabove a pre-set limit. In food processing, for example, cans can beindividually tagged with coupled-magnet devices to confirm via automaticdetection that individual cans have achieved pre-setsterilization/thermal treatment levels. Alternatively, for specificproducts (e.g., refrigerated foods), attainment of higher temperaturesis undesirable; thus, methods and systems described herein can be usedto detect temperature abuse during the product distribution and storagecycles.

The first and second magnets of the magnetically detectable particle canbe pre-magnetized, and can be selected based on any number of desirablephysical characteristics (e.g., maximum operating temperature, size,shape, weight, material composition, and magnetic field strength).According to one embodiment, the first and second magnets can comprise amaterial selected from the group consisting of neodymium iron boron,cobalt rare earth (e.g., samarium-cobalt), aluminum-based (e.g.,aluminum-nickel), ceramic, organic, plastic-embedded metal or ceramicand combinations thereof. According to another embodiment, the magnetscan be made of special sintered neodymium-iron-boron (NdFeB) grades,such as NdFeB M series (having a maximum operating temperature of about100° C.); NdFeB H series (having a maximum operating temperature ofabout 120° C.); NdFeB SH series (having a maximum operating temperatureof about 180° C.); NdFeB UH series (having a maximum operatingtemperature of about 180° C.); and NdFeB EH series (having a maximumoperating temperature of about 180° C.).

The adhesive for attaching the magnets can be selected from an adhesivesuch as glue materials, metallic alloys, or their combinations based ontheir melting point and service temperature range characteristics. Thefollowing table, Table I, shows exemplary adhesive compositions foreutectic metallic alloys and metals: TABLE I Adhesive Compositions forEutectic Metallic Alloys and Metals Eutectic Melting Point Composition(%) (Degrees C.) Indium (In) 51/Bismuth (Bi) 32.5/Tin (Sn) 16.5 60 Sn13.1/Bi 49.5/Lead (Pb) 27.3/Cadmium (Cd)10.1 70 In 66.3/Bi 33.7 72 In41.5/Bi 48.5/Cd 10.0 77.5 Bi 57/In 26/Sn 17 79 In 29.6/Sn 16.3/Bi 54.181 Bi 51.6/Pb 40.2/Cd 8.2 92 In 44.0/Sn 42.0/Cd 14.0 93 Sn 18.0/Bi52.0/Pb 30.0 95 Sn 35.7/Bi 35.7/Pb 28.6 100 Sn 25.9/Bi 53.9/Cd 20.2 104In 33.0/Bi 67.0 109 In 52/Sn 48 118 In 74/Cd 26 123 Bi 55.5/Pb 44.5 124In 70.0/Sn 15.0/Pb 9.6/Cd 5.4 125 Sn 41.6/Bi 57.4/Pb 1.0 135 Sn 42/Bi 58138 In 97/Silver (Ag) 3 143 Bi 60.0/Cd 40.0 144 Sn 51.2/Pb 30.6/Cd 18.2145 In 97.0/Ag 3.0 146 In 99.5/Ga 0.5 153 In 100.0 156.7Additionally, the listed and similar alloys shown in Table I can be usedas the thermal release layer in a laminated composition with magneticimplants, i.e., a layer of meltable metal or alloy can be affixedbetween the paired magnets using adhesives with higher operatingtemperatures than the eutectic melting point of the release-layer alloy,such as high temperature acrylic, cyano-acrylate, silicone, and epoxyadhesives.

Preferably, the adhesive is eutectic at its melting point, thusproviding a sharp, instantaneous change from solid to liquid when themelting/release temperature is reached. Upon achieving themelting/release temperature, the adhesive force of the adhesive can beovercome by the repulsing force of the same polarity magnetic poles ofthe first and second magnets such that the magnets can be released fromone another. The magnets generate the repulsing force opposing theadhesive force because the same magnetic poles of the magnets areattached adjacent to one another.

The melting/switching temperatures of selected alloys can vary slightlydue to the variability of metallic batches and variations among suppliersources. In order to ascertain the conservative nature of themeasurements, an appropriately conservative temperature value may beassigned to the switch. According to one embodiment, the conservativetemperature can be 1 degree lower than any experimentally determinedmelting or switching point for the selected batch of alloy material.That way, both measurement errors (due thermocouple, thermometer,converter and data acquisition system variability) and material propertyerrors (due to alloy variability) can be conservative.

The adhesives can have a release temperature selected between a range ofabout −40° C. and 1000° C. Mercury can represent the lower end of thistemperature range, and Al—Ni—Co can represent the higher end of thistemperature range. According to one embodiment, the release temperatureof the adhesive can be set between about 45° C. and 160° C. About the45° low end range can represent an application to low temperaturepasteurization, and the 160° C. high end range can represent a UHTsterilization range.

Upon release, the magnets can move with respect to one another so thatopposing magnetic poles are joined. The opposing poles of the magnetsare attracted to one another and can cause the magnets to realign withrespect to one such that opposing poles are adjacent one another. Thisjoining of opposing poles results in an addition of magnetic fieldstrengths such that the magnetic field signal is increased and can bedetected via magnetic sensors.

When two magnetized permanent magnets are in sufficiently close vicinityfor magnetic field lines to cross over and overlap, there can be adetectable physical attraction between the opposing magnetic poles. Ifthe magnets are sufficiently close and strong, this attraction causesthe coupling of opposing poles resulting in a combined magnet. Theresulting magnetic field strength is an additive combination ofindividual magnet field strengths. The combination of the magnets canhave a magnetic field strength higher than either of the individualmagnets.

FIG. 1 illustrates a schematic diagram of combining a first and secondmagnet M1 and M2 at opposing magnetic poles to achieve a combinedmagnet, generally designated CM1. Arrows AR1, AR2, AR3 represent thecomparative magnetic field strengths of first magnet M1, second magnetM2, and combined magnet CM1, respectively. The sizes of arrows AR1, AR2,and AR3 represent the corresponding field strengths of first magnet M1,second magnet M2, and combined magnet CM1, respectively. As indicated,the magnetic field strength of combined magnet CM1 is greater than themagnetic field strength of magnets M1 and M2 individually. For example,if magnets M1 and M2 are about identical and equally magnetized, thefield strength of combined magnet CMI is about double the individualfield strength of magnets M1 and M2. Arrows AR4 represents theattractive force between generated between magnets M1 and M2 due to theorientation of the opposing poles of magnets M1 and M2 adjacent oneanother.

Alternatively, if similar magnetic poles (north and north or south andsouth) of two permanent magnets are joined, there is a physicalrepulsion force that must be overcome in order to join the similarpoles. This joining can also result in the mutual cancellation ofmagnetic fields, resulting in a combined magnet of about zero magneticfield strength while the physical repulsion force remains in effect. Ifthe magnets are released and allowed to realign freely, there is firstrepulsion, and then realignment of the attracting opposite poles,resulting in increased magnetic field strength. The difference betweenthe magnetic field strengths in these configurations can be detectableby magnetic sensors.

FIG. 2 illustrates a schematic diagram of the result of combining firstand second magnets M1 and M2 at similar magnetic poles to achieve acombined magnet, generally designated CM2. In this example, the magneticfield strengths of magnets M1 and M2 (indicated by arrows AR1 and AR2,respectively) are about equal. When magnets M1 and M2 are combined toachieve combined magnet CM2, the combined magnetic field strengths ofmagnets M1 and M2 are effectively canceled or substantially reduced dueto the orientation of the poles of magnet M1 with respect to the polesof magnet M2. According to this embodiment, the opposing magnetic polesof magnets M1 and M2 are about equal and attached adjacent to oneanother to result in a zero or substantially small magnetic field forcombined magnet CM2.

The magnetic behavior shown in FIG. 2 can be utilized in a non-contactthermomagnetic switch system based on forcing magnets M1 and M2 toattach at similar magnetic poles. Magnets M1 and M2 can be attached atthe similar poles by an adhesive such as a thermo-labile adhesive orsoldering alloy. The adhesive can include a melting/release pointtemperature at which point the repulsion force of magnets M1 and M2overcomes the adhesive force of the adhesive to release of magnets M1and M2 from attachment at the similar magnetic poles. After magnets M1and M2 are released, magnets M1 and M2 can naturally realign due to themagnetic attraction between opposing magnetic poles such that theopposing magnetic poles of magnets M1 and M2 are adjacent. Thus, thenatural realignment of magnets M1 and M2 is determined by heating to themelting/release temperature of the adhesive. This dictates a basis forthe selection of adhesives, such as thermo-labile adhesive or solderingalloy, wherein their selection is based on their thermal breakdown pointor melting point. The change in magnetic field strength caused by thisrealignment to the natural coupling of opposite poles can cause adetectable change in magnetic field strength level, and thus a way toremotely detect the time and location of a desired temperature levelevent.

FIGS. 3A, 3C, and 3E, and FIGS. 3B, 3D, and 3F illustrate differentstates of a magnetically detectable particle, generally designated DP,during heating from a temperature below a predetermined conservativetemperature to a temperature above the predetermined temperature.Referring specifically to FIGS. 3A, 3C, and 3E, schematic diagrams ofparticle DP in a state below a predetermined conservative temperature isillustrated. Particle DP can comprise a first and second magnet M1 andM2 having north magnetic poles N1 and N2, respective, and south magneticpoles S1 and S2, respectively. In this arrangement of magnets M1 and M2with respect to one another, the magnetic fields of magnets M1 and M2are effectively reduced and can be effectively canceled if magnets M1and M2 have about the same magnetic field strength. In this arrangement,there is also a repulsion force between magnets M1 and M2.

Referring to FIGS. 3A, 3C, and 3E, particle DP can also comprise anadhesive A for attaching magnets M1 and M2 at or proximate to northmagnetic poles NI and N2 , including an embodiment as shown in FIG. 3Ewherein pole N2 is attached between poles NI and SI. Thus a detectableparticle of the presently disclosed subject matter can comprise bothperfect and non-perfect pole alignments. In some embodiments, aproximate alignment provides a detectable magnetic field strength thatcan be used for residence time detection upstream from the point of thethermal switch occurrence. Adhesive A can include a melting/releasetemperature equivalent to the predetermined conservative temperature.Above the melting/release temperature, the repulsion of magnets M1 andM2 overcomes the adhesive force of adhesive A for releasing magnets M1and M2. The process of releasing magnets M1 and M2 can be irreversible.In this embodiment, adhesive A is selected to have a release temperatureequal to a predetermined conservative temperature.

Referring specifically to FIGS. 3B, 3D, and 3F, schematic diagrams ofparticle DP in a state above the predetermined temperature isillustrated. After magnets M1 and M2 are released, magnets M1 and M2 cannaturally realign due to the magnetic attraction between opposingmagnetic poles S1 and N2 such that the opposing magnetic poles S1 and N2are adjacent. Alternatively, magnets M1 and M2 can naturally realign dueto the magnetic attraction between opposing magnetic poles S2 and N1such that the opposing magnetic poles S2 and N1 are adjacent. The changein magnetic field strength caused by this realignment due to the naturalcoupling of opposite poles S1 and N2 can cause a detectable change inmagnetic field strength level, and thus a way to remotely detect thetime and location of a desired temperature level event. In thisembodiment, the magnetic field strength of particle DP is increased fromabout zero to about the equivalent of adding the magnetic fieldstrengths of magnet M1 and M2.

Referring now to FIGS. 3G-3I, schematic diagrams of the assembly andoperation of one embodiment of a magnetically detectable particle DP ispresented. In this embodiment a pair of combined magnets CM1 and CM2,wherein each combined magnet CM1 and CM2 comprises multiple magnets M1and M2, and M3 and M4, respectively, is assembled by attaching opposingpoles S1 and N2 , and N3 and S4, respectively, using a thermo-resistantadhesive TRA. Combined magnets CM1 and CM2 are then attached at orproximate to same poles S2 and S3 by adhesive A, and combined magnetsCM1 and CM2 respectively function as a single magnet within thefunctional pair that define detectable particle DP.

Referring specifically to FIGS. 3H and 3I, a schematic diagram ofparticle DP in a state below and above a predetermined temperature isillustrated. After combined magnets CM1 and CM2 are released, combinedmagnets CM1 and CM2 can naturally realign due to the magnetic attractionbetween opposing magnetic poles S2 and N4 such that the opposingmagnetic poles S2 and N4 are adjacent. Alternatively, combined magnetsCM1 and CM2 can naturally realign due to the magnetic attraction betweenopposing magnetic poles S3 and N1 such that the opposing magnetic polesS3 and N1 are adjacent. The change in magnetic field strength caused bythis realignment due to the natural coupling of opposite poles can causea detectable change in magnetic field strength level, and thus a way toremotely detect the time and location of a desired temperature levelevent. In this embodiment, the magnetic field strength of particle DP isincreased from about zero to about the equivalent of adding the magneticfield strengths of combined magnets CM1 and CM2.

Referring now to FIGS. 3J-3L, carrier particles CP comprising multipledetectable particles DP are disclosed. In FIG. 3J, detectable particlesDP comprising two magnets each, all assembled using the same adhesive A1with release temperature T1, are disposed in interior portion IP ofcarrier particle CP. In FIG. 3K, detectable particles DP comprising twomagnets each, assembled using different adhesives A1, A2 and A3, eachhaving a different release temperature T1, T2, and T3, respectively, aredisposed in interior portion IP of carrier particle CP. In FIG. 3L,detectable particles DP comprising two or magnets each, all assembledusing the same adhesive A1 with release temperature T1, are disposed ininterior portion IP of carrier particle CP.

Referring to FIG. 4, a schematic diagram of the principle of forcedcoupling and fixing similar magnets MI and M2 is illustrated. Magnets M1and M2 can individually generate a magnetic field. Magnets M1 and M2 canthen be attached at similar magnetic poles (e.g., north magnetic polesor south magnetic poles) via adhesive A. Again, a repulsion force isgenerated between magnets M1 and M2 because they are positioned togetherat similar magnetic poles.

For the specific application of flow monitoring of multiphase foodsundergoing continuous thermal treatment, it can be useful to have anassociated level of magnetic field strength with the particle prior tothe point at which the predetermined conservative temperature isachieved. In this way, the particle can be followed through the systemand its residence time monitored and recorded in the system componentspreceding the actual location of the temperature switch occurrence.According to one embodiment, this can be achieved by providing amagnetically detectable particle having two dissimilar magnets.

FIGS. 5A and 5B illustrate different states of a magnetically detectableparticle, generally designated P, having dissimilar magnets M1 and M2.The two states are above and below a predetermined conservativetemperature. Referring specifically to FIG. 5A, a schematic diagram ofparticle DP in a state above the predetermined conservative temperatureis illustrated. Particle DP can comprise a first and second magnet M1and M2 having north magnetic poles N1 and N2 , respective, and southmagnetic poles S1 and S2, respectively. In this arrangement of magnetsM1 and M2 with respect to one another, magnets M1 and M2 can generate adetectable magnetic strength level because magnet M1 and M2 havedifferent strength levels. In particular, magnet M2 has a highermagnetic strength than magnet M1. In this arrangement, there is also arepulsion force between magnets M1 and M2. Below the predeterminedtemperature, there is a low but detectable magnetic field strength,which can substantially increase once the predetermined temperature hasbeen reached. Particle DP is useful in this state for tracking particleDP before heating above the predetermined conservative temperature.

Referring now to FIG. 5B, a schematic diagram of particle DP in a stateabove the predetermined conservative temperature for releasing magnetsM1 and M2 from one another is illustrated. Magnets M1 and M2 naturallymove with respect to one another such that opposite magnetic poles S1and S2 are adjacent. In this configuration, magnets M1 and M2 generate adetectably higher magnetic field than in the state of particle DP shownin FIG. 5A.

Two different levels of magnetic field strength according to temperaturelevels can be achieved with a particle including a three-magnetconfiguration. FIGS. 6A and 6C, and FIGS. 6B, 6D, and 6E illustratedifferent states of a magnetically detectable particle, generallydesignated DP, having a first, second, and third magnet M1, M2, and M3during heating from a temperature below a predetermined conservativetemperature to a temperature above the predetermined temperature.Referring specifically to FIGS. 6A and 6C, schematic diagrams ofparticle DP in a state below a predetermined conservative temperature isillustrated. Magnets M1, M2, and M3 can include north magnetic poles N1,N2, and N3, respectively, and south magnetic poles S1, S2, and S3,respectively. North magnetic pole N1 of magnet M1 can be attached tosimilar north magnetic pole N2 of magnet M2 via a first adhesive A1.South magnetic pole S2 of magnet M2 can be attached to south magneticpole S3 of magnet M3 via a second adhesive A2. Adhesives Al and A2 canbe selected to have the same release temperature T1, equal to thepredetermined conservative temperature. Thus, when adhesives A1 and A2are reach a temperature greater than the release temperature, magnets M1and M3 can be released from magnet M2 due to the repulsive force betweenmagnet M2 and magnets M1 and M3. In this embodiment, adhesives A1 and A2are selected to have a release temperature equal to a predeterminedconservative temperature.

Referring now to FIGS. 6B, 6D, and 6E, schematic diagrams of particle DPin a state above the predetermined conservative temperature isillustrated. Upon release via adhesive A1, magnet M1 can move withrespect to magnet M2 such that south magnetic pole S1 is adjacent tonorth magnetic pole N2 of magnet M2. Additionally, upon release viaadhesive A2, magnet M3 can move with respect to magnet M2 such thatnorth magnetic pole N3 is adjacent to south magnetic pole S2 of magnetM2. The resulting magnetic filed of particle DP is about the total ofthe magnetic fields of magnets M1, M2, and M3. According to oneembodiment, magnets M1, M2, and M3 can have different magnetic fieldsstrengths. Alternatively, magnets M1 and M3 can have the same magneticfield strength, and magnet M2 can have a magnetic field strength greaterthan magnets M1 and M3.

Referring to FIG. 6F, detectable particles DP comprising more than twomagnets each (e.g. three magnets), all assembled using the same adhesiveA1 with release temperature T1, are disposed in interior portion IP ofcarrier particle CP.

It can also be useful to have two or more temperature set-point switchlevels, e.g., a lower and progressively higher ones to enable detectionof times and locations of achievement of multiple predeterminedtemperature levels. FIGS. 7A-7C illustrate different states of amagnetically detectable particle, generally designed DP, operable atthree different magnetic field strength levels for indicating threedifferent predetermined temperature levels are illustrated. Particle DPcan include magnets M1, M2, and M3. Referring specifically, to FIG. 7A,a schematic diagram of particle DP in a state with its temperature belowa first predetermined conservative temperature T1 is illustrated.Magnets M1, M2, and M3 can include north magnetic poles N1, N2, and N3,respectively, and south magnetic poles S1, S2, and S3, respectively.South magnetic pole S2 of magnet M2 can be attached to south magneticpole S3 of magnet M3 via a first adhesive A1. North magnetic pole N1 ofmagnet M1 can be attached to similar north magnetic pole N2 of magnet M2via a second adhesive A2. In this state, the magnetic field strength ofparticle DP is at a low/zero level.

Adhesives A1 and A2 can be selected to have different releasetemperatures such that magnet M1 releases from magnet M2 at a differenttemperature than magnet M3 releases from magnet M2. Adhesive A1 isselected such that magnet M3 releases from magnet M2 when thetemperature of adhesive A1 rises above a predetermined temperature T1.Adhesive A2 is selected such that magnet M1 releases from magnet M2 whenthe temperature of adhesive A2 rises above a predetermined temperatureT2. According to this embodiment, predetermined temperature T2 isgreater than temperature T1. Thus, as the temperature of particle DPrises, magnet M1 releases from magnet M2 before magnet M3 releases frommagnet M2.

FIG. 7B illustrates a schematic diagram of particle DP in a state whenthe temperature of particle DP is between temperature T1 and temperatureT2. When the temperature rises above temperature T1, magnet M3 can bereleased from magnet M2 and move with respect to magnet M2 such thatnorth magnetic pole N3 is adjacent south magnetic pole S2 of magnet M2.The magnetic field strength of particle DP is at an intermediate levelin this state.

FIG. 7C illustrates a schematic diagram of particle DP in a state whenthe temperature of particle DP is greater than temperature T1 and T2.When the temperature rises above temperature T2, magnet M1 can bereleased from magnet M2 and move with respect to magnet M2 such thatsouth magnetic pole S1 is adjacent north magnetic pole N2 of magnet M2.The magnetic field strength of particle DP is at a high level in thisstate. In some embodiments, the process of releasing magnets M1 and M3via attachment by adhesives A2 and A1, respectively, is irreversible.

Referring now to FIGS. 7D-7G, carrier particles CP comprising multipledetectable particles DP are disclosed. In FIG. 7D, detectable particlesDP comprising three magnets each (as an example of an embodiment withmore than two magnets each), assembled using adhesives A1, A2, A3, andA4, each with different respective release temperatures T1, T2, T3, andT4, are disposed in interior portion IP of carrier particle CP. In FIGS.7E-7G, detectable particles DP comprising two or more magnets each,assembled using different adhesives A1, A2 and A3, having differentrespective release temperatures T1, T2, and T3, respectively, aredisposed in interior portion IP of carrier particle CP.

A still further alternative way to have more than a single temperatureswitch is to add coupled magnet pairs to the same space with an initialcoupled identical magnet pair as depicted in FIGS. 3A, 3B, and 4 (andoptionally a single non-coupled magnet for residence time measurementpurpose).

If all magnets of a particle (such as particle DP shown in FIGS. 7A-7C)are identical, the change in the magnetic field strength upon achievingeach successive predetermined switch temperature should be approximatelydouble the single magnet strength. Therefore, using identical magnetpairs for successive temperature switches and a single initial magnetfor residence time determination (RTD), for five successive switchtemperatures, the sequence of magnetic field strength increase should beas follows:

-   -   Below Temp1: 1×    -   At and above Temp1 but below Temp2: 3×    -   At and above Temp2 but below Temp3: 5×    -   At and above Temp3 but below Temp4: 6×    -   At and above Temp4 but below Temp5: 9×    -   At and above Temp5: 11×

The following table, Table II, shows a conservative flow approach toimplanting multiple magnetic pair switches into the carrier cavities ofsimulated 0.5 inch cube food particles (alternative target particleweights are given and theoretical number of implantable fixed magnetpairs with a mass of 0.06 grams each). Depending on the material usedand carrier particle design, in theory ten or more magnet pairtemperature switches could be implanted in every particle. The finalfunctional pairs can be larger than 0.06 grams to facilitate detection.Furthermore, the reduced number of increments can simplify the detectionof stepwise temperature switch signal changes. TABLE II ConservativeFlow Approach to Implanting Multiple Magnetic Pair Switches WEIGHTWEIGHT WEIGHT WEIGHT WEIGHT WEIGHT grams grams grams grams grams grams ½inch cube ½ inch cube ½ inch cube ½ inch cube ½ inch cube ½ inch cube1.00 density 1.01 density 1.02 density 1.03 density 1.04 density 1.05density 1.01 1.02 1.03 1.04 1.05 1.27 2.048383 2.06886683 2.089350662.10983449 2.13031832 2.15080215 0.82 1.67967406 1.67967406 1.679674061.67967406 1.67967406 1.67967406 Free space (grams) 0.368708940.38919277 0.4096766 0.43016043 0.45064426 0.47112809 # Magnet pairs6.145149 6.486546167 6.827943333 7.1693405 7.510737667 7.852134833 (0.06grams ea

Bubble space 0.256047875 0.256047875 0.256047875 0.256047875 0.2560478750.256047875 (¼ inch cube) # Magnet pairs 4.267464583 4.2674645834.267464583 4.267464583 4.267464583 4.267464583 (0.06 grams) Temperature10.41261358 10.75401075 11.09540792 11.43680508 11.77820225 12.11959942switch pairsTable II demonstrates the application of a number of paired magnets forimplantation. The number of implanted magnetic pairs can be smaller,typically about two or less, allowing for larger, heavier magnets to beused for yielding higher initial (unswitched) magnetic signal levels aswell as higher signal levels after the switch/melting has occurred.

In yet another embodiment, magnets (such as magnets M1 and M2 shown inFIGS. 3A and 3B) can be assembled by using an adhesive comprising a flatpiece of suitable metal alloy (foil or thin sheet grade). Appropriateadhesives (such as adhesive A shown in FIG. 3A) include any adhesivecapable of affixing dissimilar metal pieces to each other and that can,once set, withstand temperatures in excess of any process temperatureencountered during processing. Appropriate adhesives can be single ormulti-component epoxies, epoxy films, or special thermo-resistantcyanoacrylate adhesives. The curing temperature of the adhesive (ifcuring is necessary) should be below the lowest melting temperature ofany meltable element (e.g., metallic alloy) used in the assembly of theparticle.

FIG. 8 illustrates a schematic diagram of attaching a first and secondgmagnet M1 and M2 via a metal alloy MA and thermo-resistant adhesivesTRA1 and TRA2. Magnets M1 and M2 can comprise a north magnetic pole N1and N2, respectively, and a south magnetic pole S1 and S2, respectively.Metal alloy MA can be attached to north magnetic pole N1 and northmagnetic pole N2 via adhesives TRA1 and TRA2, respectively. Metal alloyMA can comprise a thin layer foil having a release temperature forreleasing magnets M1 and M2 from one another above the predeterminedtemperature. Metal alloy MA can be selected having a release temperatureequal to a predetermined conservative temperature. Adhesives TRA1 andTRA2 can have a curing temperature below the melting point of metalalloy MA. Adhesives TRA1 and TRA2 can also have a maximum servicetemperature above any temperature encountered during processing andoperation.

Exemplary epoxy adhesives for the embodiment shown in FIG. 8 include butare not limited to Master Bond Polymer System Supreme 3HT-80 (singlecomponent, curing temperature 80° C./175° F.; maximum servicetemperature of 350° F.) and Master Bond EP62-1 (two component, curingtemperature 60-100° C.; maximum service temperature of 400° F.), bothproduced by Master Bond Inc. of Hackensack, N.J., United States ofAmerica. Examples of appropriate cyanoacrylic adhesives are TX-1500(room temperature cure, maximum service temperature 150° C.) produced byIntek Adhesives Ltd., of Northumberland, England; POWERBOND™ (roomtemperature cure, maximum service temperature 180° C.) available fromPermabond International Corporation of New York, N.Y., United States ofAmerica; and PERMABOND™ C910 produced by Permabond, a division ofNational Starch and Chemical, Bridgewater, N.J., United States ofAmerica.

One advantage of the adhesive metal alloy embodiment (an example ofwhich is shown in FIG. 8) is the capability to assemble the magnets attemperatures significantly lower than the melting points of metallicalloys (such as metallic alloy MA shown in FIG. 8). This capacityincreases the speed and reliability of assembly, and makes possibledevice combinations that could be very difficult to assemble if theassembly had to rely on melting of the metallic alloy interfaces.

FIG. 9 illustrates an experimental system, generally designated ES, foruse in demonstrating the magnetically detectable particles, carrierparticles, and related devices described herein. Experimental system EScan include glass tubes GT positioned in a laboratory heating well andfilled with propylene glycol in order to achieve food sterilizationtemperatures (above 140° C.) without substrate boiling. Glass tubes GTcan be covered externally with larger stainless steel tubes ST todemonstrate the ability of system ES to detect magnetic field strengthchanges through stainless steel, a standard food process equipmentmaterial. Four GMR magnetic field sensor assemblies SA can be attachedto an external surface of stainless steel tube ST and signal fromsensors S can be wired to a computer data acquisition system (not shown)and recorded using a conventional computer (such as an INTERNATIONALBUSINESS MACHINES™ (IBM) compatible computer available from IBMCorporation of White Plains, N.Y., United States of America) and anoperating system (such as the WINDOWS™ operating system available fromMicrosoft Corporation of Redmond, Wash., United States of America).Sensors S can be a GMR magnetic sensor having wired connections to thecomputer data acquisition system. Sensor assemblies SA can be housed inprotective polycarbonate tubes affixed to the surface of stainless steeltubes ST.

FIGS. 10-15 illustrate further aspects of experimental system ES shownin FIG. 9. Referring to FIG. 10, a still image of a simulated particleSP containing a coupled magnet sensor/detector is illustrated. Simulatedparticle SP can include a cargo bay CB for containing a coupled magnet(not shown). Simulated particle SP can be fabricated from polypropyleneand nylon material in order to withstand the sterilization temperatures.The magnet couples can be constructed using adhesives and placed in thecenter of simulated particle SP, sealed with a machined screw consistingof the same material as simulated particle SP.

Referring to FIG. 11, a still image of another simulated particle SPincluding a thermocouple lead TL having contact with a magnet assembly(not shown) in the center is illustrated. Combined magnet-implant loadedparticles SP can be fitted with thermocouple leads with hot junction incontact with the combined magnet for providing a temperature monitoringfeed to the experimental system (such as experimental system ES shown inFIG. 9).

Referring to FIG. 12, a still image of simulated particle SP (shown inFIG. 11) with experimental system ES. Simulated particle SP is loweredinto a heated test tube TT via an ex-centric rotating shaft providing acontrolled up-down motion. During experimentation, simulated particle SPwas repeatedly raised and lowered while being monitored by sensorassemblies SA. Data was recorded from the thermocouple (temperature inthe center of particle SP). Sensor assemblies SA can provide temperatureswitch point calibration and recording.

Referring to FIG. 13, a still image of a data acquisition system,generally designated DAS, including a display D for presenting acquiredtemperature information and magnetic field strength data. Thetemperature can be acquired from a single type T thermocouple. Themagnetic field strength data can be acquired from sensor assemblies SA(shown in FIG. 9).

FIGS. 14A-14D illustrate different still images of a triple magnetassembly MA being assembled in a simulated particle SP. FIGS. 14A-14Bshow two magnets joined together by solder plus a single magnet(thermocouple-attached) for temperature and residence time measurement.FIGS. 14C-14D show simulated particle SP enclosing the magnet assemblywith a cap CP.

FIG. 15 illustrates a still image of a magnet pair MP with a U.S. pennyUSP for providing a size scale perspective. Magnet pair MP can be about0.07 grams.

FIGS. 16-30 illustrate different graphs and other illustrations ofexperimental results obtained by testing various particles as describedin this section under experimental conditions. Unless otherwiseindicated, the particles were tested using experimental system ES shownin FIG. 9.

FIG. 16 illustrates a graph of magnetic field strength from twonaturally aligned identical magnets with no heating.

FIG. 17 illustrates a graph of magnetic field strength from two alignedand attached magnets with no heating. The magnets have similar magneticpoles attached with an adhesive.

FIG. 18 illustrates a graph of magnetic field strength from two alignedand attached with heating. The magnets have similar magnetic polesattached with an adhesive. The magnets are heated until thepredetermined conservative temperature associated with the releasetemperature of the adhesive is reached. The graph shows a detectabledifference in magnetic field strength above the predeterminedconservative temperature.

FIG. 19 illustrates a graph showing applied temperature versus magneticfield strength. The temperature is applied to an identical magnet pairattached via an adhesive. The adhesive had a thermal breakdowntemperature of about 110° C.

FIG. 20 illustrates a graph showing applied temperature versus magneticfield strength. The temperature is applied to a non-identical magnetpair attached via an adhesive. The adhesive was a thermo-labile adhesivewith a thermal breakdown temperature of about 110° C. Low-level magneticfield strength is evident up to the breakdown temperature. Above thebreakdown temperature, high magnetic field strength was detected.

FIG. 21 illustrates a graph showing applied temperature versus magneticfield strength. The adhesive was a soldering alloy with a thermalbreakdown temperature of about 137° C. Low-level magnetic field strengthis evident up to the breakdown temperature. Above the breakdowntemperature, high magnetic field strength was detected.

FIG. 22 illustrates a graph showing applied temperature versus magneticfield strength. The increasing heat was applied to a single identicalmagnet pair placed with a pair of identical force—aligned magnets withthe same magnetic poles adjoining and fixed using a soldering alloy witha melting temperature of 137° C. (eutectic). Above the meltingtemperature, a higher multiplied magnetic field strength was detected.

FIGS. 23-27 illustrate graphs of experimental results obtained bytesting the device shown in FIGS. 3A and 3B with an adhesive comprisinga metal alloy. The metal alloy has a melting point of 138.3° C. Theexperimental results shown in FIGS. 23-27 show that the magnetic fieldstrength increases substantially at about 138.3° C.

FIGS. 28-30 illustrate graphs of experimental results obtained bytesting the device shown in FIGS. 3A and 3B with an adhesive comprisinga metallic alloy. The metallic alloy has a melting point of 123.9° C.The experimental results shown in FIGS. 28-30 show that the magneticfield strength increases substantially at about 123.9° C.

FIG. 31 illustrates a graph of magnetic field strength versustemperature obtained using the assembly shown in FIGS. 5A and 5B, whichwas tested using experimental system ES shown in FIG. 9.

FIG. 32 illustrates a graph of magnetic field strength versustemperature obtained using the assembly shown in FIGS. 6A and 6B, whichwas tested using experimental system ES shown in FIG. 9.

FIG. 33 illustrates a graph of magnetic field strength versustemperature obtained using the assembly shown in FIG. 7, which wastested using experimental system ES shown in FIG. 9.

FIG. 34 illustrates a schematic diagram of an exemplary system,generally designated 3400, for conservative evaluation, validation, andmonitoring of thermal processing. System 3400 can comprise particles P,an infeed hopper IH, pipe PI, sensors S1, S2, S3, and S4, and computeracquisition system CAS. Sensors S1, S2, S3, and S4 each further compriseoptional flux-concentrating strips FCS and can be mounted along apredetermined length of pipe PI, wherein the predetermined length isdefined by points L1 and L2. Power source PS can provide power tosensors S1, S2, S3, and S4.

Referring to FIG. 34, optional flux-concentrating strips FCS for sensorsS1, S2, S3, and S4 can be mounted in a parallel manner with the ends ofoptional flux-concentrating strips FCS in a parallel or side-by-sideoverlap as represented by overlap points OP. A1ternatively, optionalflux-concentrating strips FCS can be wrapped around pipe Pi, can bemounted in a “zig-zag” pattern on pipe PI or in any other suitablemanner, with the ends of optional flux-concentrating strips FCS beingoriented in a parallel or side-by-side overlap as represented by overlappoint OP.

Continuing with reference to FIG. 34, particles P can include anysuitable magnetically detectable particle DP such as detectableparticles DP shown in FIGS. 3A, 3B, 4, 5A, 5B, 6A, 6B, 7A, 7B, 7C, and 8for providing a magnetic signal change depending on temperature.Particles P can also comprise a carrier particle CP having an interiorportion IP defined therein for holding detectable particle DP. Carrierparticle CP can comprise shield material selected to provide aconservative heating temperature to detectable particle DP.Additionally, one of sensors S1, S2, S3, and S4 can optionally becalibrated to detect a signal from particles P at a temperature belowthe predetermined temperature for the respective particles P.

Continuing with reference to FIG. 34, when in use system 3400 canaccommodate the insertion of particles P via infeed IH into pipe PI.PIpe PI can represent a continuous thermal processing apparatus.Particles P can be carried by continuous stream of material flowingwithin pipe PI and can be monitored for a magnetic signal changebeginning at point L1. When interior portion IP of particle DP reachesthe respective predetermined temperatures (also referred to herein as“switch temperature” or “temperature switch”) for each particle DP, theadhesive (such as adhesive A shown in FIGS. 3A and 3B) release magnets(such as magnets M1 and M2) of detectable particle DP such that themagnets reorients as described herein to change magnetic field strength.The change in magnetic field strength can be detected continuously bysensors S1, S2, S3, and S4 over a predetermined length of pipe PIdefined by points L1 and L2, for a period of time, or combinationsthereof. The predetermined length defined by points L1 and L2 cancomprise a length wherein a “cold spot” within particle DP is maintainedat or above the predetermined temperature for a sufficient time toaccomplish desired thermal treatment of the product flowing in pipe PI.The detection of the signal along this predetermined length can berecorded by computer acquisition system CAS for graphical display, forprintout in a word processing report, or for other review and evaluationby a user. Computer acquisition system CAS can represent a device fordigital recording of output (e.g., signals from particles P) fordocument storage, e.g., as computer data files, and subsequent retrievaland analysis purposes. Other such devices can include digital cameras.Another representative such device can include a video camera, which canbe employed for analog (video tape) recording for documentation storageand subsequent retrieval and analysis purposes. Another such deviceprovides for video recording onto a VCR tape off the actual computerdisplay signal, that is, without using a camera, but rather through aconverter to a regular NTSC video. This converter can be built into avideo card in computer acquisition system CAS or can be external. Thisconverter allows recording onto a tape of anything that is displayed onthe computer screen—meaning that as different signals at differentlocations of particles P flowing through system 3400 are observed, theycan be recorded on the video tape. A still camera can be employed at anappropriate shutter speed and other settings to record output, e.g.,signals from particles P. Video and still cameras can be operativelyconnected to system 3400 for automated activation upon detection of asignal or other desired event, and can be employed in an embodiment ofsystem 3400 comprise transparent pipe sections or a view-port.

According to another embodiment, adhesives can also be selected torelease magnets during any type of environmental condition, such assurrounding physical and/or chemical conditions. For example, accordingto one embodiment, an adhesive can be selected so that it degrades whenexposed to an analyte, such as a selected chemical component orproperty, including water, carbon dioxide, and an analyte having aparticular pH. The adhesives can also be sensitive to pressure and/orlight for release of the magnets at a predetermined threshold ofpressure and/or light, respectively. For example, the adhesive candetect and release at a predetermined intensity or frequency of light.According to one embodiment, an adhesive can selected that is sensitiveto an increase in the concentration of carbon dioxide. The applicationof this adhesive to the above described magnets can be used to detectbacterial spoilage within hermetically sealed packages of foods orbiomaterials without destroying or opening the package.

An adhesive can also be selected that is sensitive and/or degradablewhen exposed to an increase or decrease in pH value. The application ofthis adhesive to the above described magnets can be used in combinationwith paired magnets to detect other modes of spoilage in sealedpackages. For example, this configuration can detect the generation ofinorganic or organic acids as byproducts of bacterial fermentationprocesses.

A water-soluble adhesive can be used to irreversibly detect melting offrozen products. A paired magnets implant can be glued with awater-soluble adhesive and placed on top of a frozen product, sealedwithin a small sealed bag with some ice—if the melting point wasexceeded causing the ice to melt—the resulting liquid water coulddissolve the adhesive—causing an irreversible switch of the magnets—thusthe event where the temperature exceeded the melting point would berecorded.

These examples are only some of the possible alternative uses of theinvention. The subject matter described herein provides for therecording and non-contact detection of a variety of changes that areconducive to the application of magnetic field sensing and the use of anadhesive selected to be sensitive or degradable under a specific singleor a set of conditions—thermal, chemical, physical, and combinationsthereof.

II. Conservative Carrier Particles for Detectable Particles

Monitoring and validation of thermal pasteurization and sterilizationprocesses can employ simulated, carrier food particles for carrying adetectable particle as disclosed herein. Such a combination of carrierand detectable particles can advantageously exhibit conservative flowand thermal characteristics. A method is provided including a systematicimplementation of several heretofore un-integrated, mutually limitingdesign rules and principles for selecting and defining the geometry andfabrication procedure for a carrier particle. In particular, anintegrated approach is provided for designing simulated carrierparticles that about match the conservative flow behaviorcharacteristics of a selected target particle (e.g., thosecharacteristics conducive to fabrication and providing sufficientcavity/cargo bay size for selected detectable particles).

Using these design criteria as a basis, the methods described herein canfacilitate the design and fabrication of simulated food particles (i.e.,a carrier and detectable particle combination having the sameconservative behavior characteristics as a selected target food particleor biomaterial present in the processed product) from suitablematerials, such as polymers. In some embodiments, these methods can beuseful when the determination of wall thickness of the carrier particleis critical for the safety and quality of the food product to beprocessed.

As used herein, a “target particle” is any type of exemplary foodparticle exhibiting slow heating and/or fast moving characteristics in abatch or continuous stream of material. Slow heating and/or fast movingcharacteristics can be considered “conservative behaviorcharacteristics” because these foods particles are those that are likelyto be the slowest particles to achieve a predetermined temperature inthe cold spot of the particle when used in a batch or continuous streamof material.

As used herein, a “carrier particle” is a particle that is used forenclosing a detectable particle as disclosed herein for the purpose ofmonitoring and validation of continuous thermal processing of multiphasematerials, such as food products. “Conservative thermal behavior” ispresent when the thermal protection provided by the carrier particle toits cavity carrying the detectable particle is at least equivalent to orgreater than the thermal protection provided by a target particle to itscold spot under similar heating conditions. A conservative design of thecarrier particle is targeted to ensure product safety. “Conservativedesign” means that the thermal protection provided by the carrierparticle to its cavity carrying the detectable particle is at leastequivalent to or greater than the conservative behavior characteristicsprovided by the target food particle to its cold spot (typically itsgeometric center), under similar heating conditions. A minimallyconservative design is desired, since an over-conservative design canresult in unnecessary loss of product quality and an under-conservativedesign will result in an unsafe product.

A method for providing a carrier particle design for a batch orcontinuous stream of material can include two main steps—determiningconservative behavior characteristics of a target particle used in abatch or continuous stream of material, and determining material anddimensions for a carrier particle design about matching the conservativebehavior characteristics of the target particle. Conservative behaviorcharacteristics of a target particle can be determined by selecting andsimulating an exemplary food particle or product that is likely to bethe fastest moving and/or slowest heating particle in a batch orcontinuous stream of material. Next, material and dimensions for acarrier particle design can be determined by selecting and simulatingvarious carrier particle designs to achieve a carrier particle designabout matching the conservative behavior characteristics of the targetparticle. An actual target particle can be fabricated with the selectedmaterials and dimensions. The actual target particle can be insertedwith a detectable particle for temperature detection in a batch orcontinuous stream of material.

FIG. 35 illustrates a schematic diagram of a computer system, generallydesignated CS, which can facilitate the design of a carrier particleabout matching the conservative behavior characteristics of a selectedtarget particle. Computer system CS can include a conventional computerCOMP having a memory MEM for storing conservative behaviorcharacteristics of different target particles used in a batch orcontinuous stream of material. Memory MEM can also be operable to inputand output data and code to and from spatial simulation engine SSE.Computer COMP can also include a spatial simulation engine SSE forsimulating material and dimensions of a carrier particle design formatching the conservative behavior characteristics of the targetparticle. Computer system CS can also include a user interface UI forreceiving user commands and a display D for displaying simulationresults and user interface information to an operator. The functions ofspatial simulation engine SSE, memory MEM, display D, and user interfaceUI in providing a carrier particle with conservative behaviorcharacteristics in a batch or continuous stream of material will bedescribed in further detail herein with respect to FIG. 36.

Referring now to FIG. 36, a flow chart, generally designated 3600, isshown which illustrates a process for providing a carrier particlehaving materials and dimensions to provide characteristics for thecarrier particle that about match the conservative behaviorcharacteristics of a selected target particle. As stated above, such aprocess can be at least partially performed by computer system CS. Theprocess begins at the step indicated by reference numeral 3602. In step3604, memory MEM (shown in FIG. 35) can be stored with simulationinformation for an exemplary target particle and the conditions appliedto the target particle in at least one simulation. The simulationinformation for the target particle can include the conservativebehavior characteristics of the target particle, such as conservativedimensional and thermal characteristics of the target particle. Thedimensional and thermal characteristics of the target particle can beimportant because it can determine whether the cold spot of the targetparticle reaches a predetermined temperature in a specified time under athermal process. Dimensional characteristics can include the shape andsize of the selected target particle. Thermal characteristics caninclude the specific heat, density, and thermal conductivity of theselected target particle.

Depending on the mode of heating, other simulation properties caninclude electrical conductivity, coefficient of thermal expansion,porosity, and dielectric properties such as dielectric constant,dielectric loss factor, and dielectric loss tangent. Other simulationproperties can include elasticity and particle smoothness, which caneffect a variety of heat transfer conditions, such as during continuousflow.

Exemplary target particles having conservative behavior characteristicscan include any suitable type of food product that is slow to achieve apredetermined temperature in the center of the particle in a thermalprocess. In order to provide safe food product, the center of theslowest heating food product should reach the predetermined temperaturein the applied thermal process. Such food particles can include apotato, carrot, or other suitable slow heating or target particleshaving conservative behavior characteristics. Other food and biomaterialparticles that can be simulated include meat particles, various fruitand vegetable particles, restructured particles such as tofu or cheeseparticles, texturized vegetable protein particles, solid, elastic andsoft pliable gel particles, and biomass generated by microbialfermentations or growth. Additionally, manufactured synthetic particlesof organic or inorganic origin and composition can be simulated. Thesetarget particles can include quantifiable characteristics for entry intomemory MEM (shown in FIG. 35). For example, potatoes are typicallycubical in shape, and carrots are typically cylindrical in shape. Othershapes include parallelepipeds, spheres, ellipsoids, wedges, and variousirregular shapes that can be approximated by suitable numericsimulations.

At step 3606, memory MEM can be stored with simulation information for acarrier particle design. The simulation information for the carrierparticle design can include the characteristics of different materialsfor fabricating an actual carrier particle. The materials forfabricating a carrier particle can include polymers such aspolypropylene, methylpentene copolymer (TPX), and nylon. Further, thecarrier particle material can include any suitable plastic polymermaterial as well as biopolymers (such as polysaccharide and protein gumsand gel materials) having suitable physical and thermal characteristicsfor the selected purpose. The simulation information can also includecharacteristic information on these types of carrier particles such asspecific heat, thermal conductivity, density, electrical conductivity,coefficient of thermal expansion, porosity, dielectric properties suchas dielectric constant, dielectric loss factor and dielectric losstangent. Other properties such as elasticity and particle surfacesmoothness may also play a role under a variety of heat transferconditions, especially during continuous flow. Further, the simulationinformation for the carrier particle design can also include dimensionalinformation for fabricating the actual carrier particle. The dimensionalinformation can include the shape, size, and dimensions of an exteriorof the carrier particle and an interior cavity of the carrier particlefor holding an associated detectable particle.

At step 3608, the conservative behavior characteristics of a targetparticle can be determined. Initially, an operator can select a targetparticle for modeling with computer system CS (shown in FIG. 35). Theselected target particle can be a target particle exhibitingconservative behavior characteristics in a batch or continuous stream ofmaterial. For example, the target particle can be a potato cube. Theoperator can select simulation information from memory MEM (shown inFIG. 35) for modeling a potato cube or other target particle withspatial simulation engine SSE. Spatial simulation engine SSE cansimulate the model in simulation conditions similar to those in a batchor continuous stream of material.

According to one embodiment of step 3608, simulated heat can be appliedto the target particle until its geometric center or cold spot achievesthe lethality value (F₀) of 3 minutes. This step can generate therequired hold time to achieve the desired lethality for the cold spot ofthe target particle.

Next, at step 3610, the materials and dimensions for a carrier particledesign about matching the conservative behavior characteristics of thetarget particle can be determined. Dimensions, such as shape dimensions,for a carrier particle design can be selected from memory MEM to aboutmatch the selected target particle. For example, a cubical orcylindrical shape can be selected to match a cubical potato orcylindrical carrot. Additionally, for example, a spherical shape can beselected to match a spherically-shaped target particle. Additionally, amaterial type for the carrier particle design can be selected frommemory MEM. Spatial simulation engine SSE can simulate a carrierparticle design having selected materials and dimensions to determinewhether it matches the conservative behavior characteristics of thetarget particle. Additionally, the materials and dimensions of thecarrier particle design can be adjusted to achieve a design aboutmatching the conservative behavior characteristics of the targetparticle. As disclosed further herein, the operator can also adjust thedimensions and materials of a carrier particle design with the spatialsimulation engine SSE to achieve a carrier particle design with desiredbehavior characteristics.

Generally, carrier particles can be designed and fabricated from one ormore polymer materials to emulate the shape and size of food particlesor biomaterial present in a processed product, such as a particle in abatch or a continuous stream of material. Potential polymer material forsimulated particle fabrication can be selected based on thermal andphysical criteria in order to ascertain conservative flow and aconservative heating behavior in a batch or continuously processedsystem in all lethality-delivering segments or stages of the process.

The carrier particles can be fabricated to provide the equivalentthermally conservative characteristics for any target shape, size andmaterial composition, provided the appropriate thermal and dimensionalcharacteristics are known or defined for the target particle. Typicaltarget particles are defined by material nature, shape and dimensions;for example, a ½ inch potato cube, a ⅜ inch carrot cylinder, 1 cm beefcube, etc. Target particles can also have a spherical shape.

Conservative flow behavior dictates a carrier particle construction inwhich the carrier particle belongs to the population of particles(containing identical shape and sizes) with the highest likelihood ofcontaining the fastest traveling particle. This desirable result isachieved by selecting the appropriate solid material density anddesigning the blank cargo space cavity in the particle center to balancethe target density of the composite particle and carry thethermosensitive implants. Selected densities can be between about 10kg/m³ (representing a porous material such as silica aero gel) and20,000 kg/m³ (representing a very high density solid material).According to one embodiment, the density range can be between about 250kg m³ (for simulated particles ranging between the effective density ofhollow, thin-walled particle of TPX) and 1600 kg/m³ (for a very densewater-based carrier fluid such as about 95% molasses). Very loweffective density particles can be applied to vertical heat exchangergeometries and hold tubes in order to ensure sufficiently fast upwardmovement within the population of natural target particles.

Conservative heating behavior dictates the criteria for particleconstruction in which the resulting composite particle exhibits a slowertemperature increase in both segments of lethality accumulation (i.e.,both the heater and the hold tube) than any other processed material(e.g., carrier fluid and all other used particulate food components).Desirable conservative heating characteristics for a simulated particlewere previously defined in U.S. Pat. No. 6,015,231 to Swartzel et al.,which is incorporated by reference herein. While the requirement oflowest thermal conductivity was described in that patent as desirable toprovide the desired conservative heating behavior, there is a furtherneed to define the minimally conservative characteristics in order totake advantage of positive characteristics of continuous flow thermalprocessing.

In view of the foregoing, one critical design element for the carrierparticles of the presently disclosed subject matter is the minimallyconservative particle wall dimension, i.e., the smallest necessarydimension needed for the carrier particle to provide the equivalent orgreater thermal protection to the contents of the enclosed cavity (orcargo bay) compared to a predetermined target material shape anddimension.

According to one embodiment of step 3610, the carrier particle designcan be simulated under the same heating conditions of the targetparticle in step 3608 and for the duration (hold time) determined instep 3610 to achieve the lethality value (F₀) of 3 minutes for thetarget particle. This step can generate the cross-section profilesdescribed herein of accumulated F₀ values during the same heatingprocess resulting in an F₀ value of 3 minutes in the cold spot of thetarget particle. Next, the layer of F₀ values lower than 3 minuteswithin the carrier particle design can be identified from thecross-section profiles obtained via simulation. This layer can definethe position of the wall of the internal cavity of the actual carrierparticle for carrying the detectable particle. Therefore, the layer candefine the wall thickness for fabricating the actual carrier particle. Adetectable particle placed within a cavity surrounded by a carrierparticle having a wall of this thickness and processed to an F₀lethality value of 3 minutes or greater can correspond to a processyielding at least an F₀ of 3 or more minutes for the related targetparticle.

Referring again to FIG. 36, at step 3612 , the carrier particle designcan be used as a plan for fabricating an actual carrier particle for usein a batch or continuous stream of material. The actual carrier particlecan be fabricated with the materials and have dimensions of the carrierparticle design determined to about match the conservative behaviorcharacteristics of the target particle.

According to one exemplary embodiment, a cube can be fabricated that ismade out of a selected polymer, containing an implant-compatible cavity,with a minimum wall thickness providing the equivalent of greaterthermal protection to the contents of the cavity that is provided by thetarget particle material (for example, a potato cube) to its “cold spot”or geometric center.

The critical wall dimension can be determined by simulating heating ofthe target natural material and identical shape and size of severaldifferent potential fabrication polymers, under identical thermalconditions, until the center (cold spot) of the target particleaccumulates a pre-selected time-temperature treatment combination (i.e.,lethality, as evidences by a cumulative F₀ value of 3 minutes orgreater). As referred to herein, the F₀ value is the time at a referencetemperature of 121.1° C. (250° F.) (assuming instantaneous heating andcooling) to which the entire thermal process is equivalent forconstituents with a z-value of 10° C.

The spatial simulation models of the identically sized and shapedpolymer materials are then examined to determine the depth (i.e., wallthickness) at which the same or greater equivalent lethality has beenaccumulated under same conditions and during the same time period. Thisdepth or dimension is then deemed “critical” since it provides at leastequivalent and appropriately conservative thermal protection to thecontents of the cavity contained within that dimension.

For irregularly or non-symmetrically shaped cavities that may begenerated as a result of limitations in fabrication methods andprocedures, it is generally assumed that the path of least resistance(i.e., the lowest wall thickness) represents all surrounding wallthicknesses.

The thermal energy required to bring the temperature of the contents ofthe cavity to the temperature of the wall is treated as an additionalconservative protection element. In other words, it is assumed that thecontents of the cavity reach the cavity wall instantaneously. Thisprovides an additional level of thermally conservative behaviorassurance.

FIGS. 37-40 illustrate various screen displays showing exemplarysimulation results that can be displayed on display D (shown in FIG.35). These simulations can be executed by spatial simulation engine SSE(shown in FIG. 35). These figures show the need for the minimization ofconservative properties of fabricated particles. If, for example,polypropylene is used to fabricate a carrier particle in order tosimulate heating of potato particles, and to carry a thermo-sensitiveimplant in its geometric center, considerable overheating of the targetparticle (e.g., potato) can result if this was used as a basis forthermal process establishment. Under identical simulation heatingconditions, by the time the geometric center of a solid polypropyleneparticle accumulated an equivalent lethality of 3.0 minutes, thecorresponding geometric center of a potato particle of identical sizeaccumulated an F₀ of 146 minutes for a 0.5 inch cube (FIG. 37); an F₀ of93 minutes for a ⅜ inch cube (FIG. 38); an F₀ of 133 minutes for a 0.5inch by 0.5 inch cylinder (FIG. 39) and an F₀ of 84 minutes for a ⅜ inchby ⅜ inch cylinder (FIG. 40). This level of over-processing can resultin unacceptable levels of quality degradation. It is therefore necessaryto define the criteria and approach for the construction of minimallyconservative fabricated particles relative to the target food orbiomaterial particles. This criteria can be defined on fabricatedparticle wall thickness characteristic. The fabricated particle wallthickness can be selected so that it provides at least the same degreeof thermal protection to the cavity contained within the fabricatedparticle walls as the target particle provides to its geometric center(or cold spot).

Referring specifically to FIG. 37, two screen displays 3700 and 3702show results indicating that using an overly conservative carrierparticle design can result in a potato food particle receivingcumulative lethality in its cold spot up to two orders of magnitudegreater than required for commercial sterility. Screen display 3700shows the results of simulating a 0.5 inch cubic carrier particlecomprising polypropylene in a thermal process. Spatial simulation engineSSE can receive simulation information regarding particle halfthickness, density, thermal conductivity (k), and specific heat. In thisexample, half thickness is set to 0.00635 meters, density is set to 910kg/m³, thermal conductivity is set to 0.13 W/m·k, and specific heat isset to 2343 J/kg·K. The simulation can include exposing the carrierparticle to a specified fluid and heating conditions, such as aspecified fluid density and specific heat. In this example, the fluiddensity is set to 1000 kg/m³, and the specific heat is set to 3600J/kg·K. Additionally, the simulation can include specifying productparticle load, flow rate, and initial temperature. In this example,particle load is set to 30% by volume, flow rate is set to 2 L/s, andinitial temperature is set to 20° C. The simulation can also includespecifying heating applied to the carrier particle, such as the fluid toparticle interface convective heat transfer coefficient (h_(fp));heating time; fluid temperature at heat exchange; and whether the fluidtemperature increases exponentially or linearly. In this example, h_(fp)is set to 1000 W/m²·K, fluid temperature at heat exchange is set to 140°C., heating time is set to 112 seconds, and the fluid temperatureincreases exponentially.

Specific heat or heat capacity range of the carrier particle can rangebetween about 122 J/(kg·C °) (representing tungsten) and 4,186 J/(kg·C°) (representing water). According to one embodiment, the specific heatof the carrier particle can range between about 900 J/(kg·C °)(representing aluminum) and 4,200 J/(kg·C °) (representing water).A1uminum carrier particles can be used for simulating thermally“liberal” behavior in order to evaluate the “thermally most abused”population segment.

Screen display 3700 can include an output section for displaying thesimulation results of applying the specified simulation conditions tothe specified carrier particle. The output section can include outputfor required holding time, required length of holding tube, centertemperature, mass average temperature, thiamine retention percentage,lysine retention percentage, and overall quality retention percentagefor a carrot and potato. In this example, the required holding time is287.2 second and the required length of holding tube is 566.8 meters.The center temperature is 129.1° C. The mass average temperature is 137°C. The thiamine retention percentage is 85.2. The lysine retentionpercentage is 95.9. The overall quality retention percentage is6.48*10⁻² and 5. 9*10⁻² for the carrot and potato, respectively.

Screen display 3702 shows the results of simulating a 0.5 inch cubic,potato target particle in a thermal process. As shown by thesimulations, the cumulative lethality received by the simulated potatois about two orders of magnitude greater than required for commercialsterility (e.g., an F₀ value of 3 minutes).

Referring to FIG. 38, two screen displays 3800 and 3802 show othersimulations applied to a carrier particle design and ⅜ inch, potato foodparticle, respectively, under similar conditions. These simulations alsoshow that the cumulative lethality received the simulated potato isseveral orders of magnitude greater than required for commercialsterility.

Referring to FIG. 39, two screen displays 3900 and 3902 show othersimulations applied to a carrier particle design and a cylindrical,potato food particle, respectively, under similar conditions. Thesesimulations also show that the cumulative lethality received thesimulated potato is several orders of magnitude greater than requiredfor commercial sterility.

Referring to FIG. 40, two screen displays 4000 and 4002 show othersimulations applied to a carrier particle design and anothercylindrical, potato food particle, respectively, under similarconditions. These simulations also show that the cumulative lethalityreceived the simulated potato is several orders of magnitude greaterthan required for commercial sterility.

FIGS. 41-51 illustrate an exemplary procedure for simulating,calculating, and selecting carrier particle designs for carrying adetectable particle for monitoring and validation of thermal processingof a multiphase food material containing a 0.5 inch potato cube.Referring specifically to FIG. 41, a schematic diagram of a cubicparticle design, generally designated 4100, for simulation by spatialsimulation engine SSE is illustrated. Cubic particle design 4100 can beused to calculate the sequential lethality (F₀ value) increments duringheating for a variety of materials. Cubic particle design 4100 can bedivided into smaller cubicles, generally designated 4102, including acubicle 4104 at the center of particle design 4100 and other cubiclesextending to the exterior of cubic particle design 4100. In thisembodiment, design 4100 is divided into smaller cubicles 4100 forfacilitating the simulation and observation of heating from the exteriorof cubicle to the center, the area of greatest interest. Cubic particledesign 4100 can be used in simulating heating applied to the exterior ofdesign 4100 and observing the effect of the heating to cubicle 4104, thearea of interest.

FIG. 42 illustrates a screen display 4200 showing exemplary heatsimulation for a cubic, potato target particle design 4100 (shown inFIG. 41) to an F₀ value of 3 minutes in the center. The required holdingtime is about 131.4 seconds. In this simulation embodiment, targetparticle design 4100 has a coefficient of thermal diffusivity (α) of1.63*10⁻⁷ m²/s. The coefficient of thermal diffusivity is a materialcharacteristic which describes the rate at which heat is conductedthrough the material. The coefficient of thermal diffusivity is relatedto thermal conductivity k, specific heat c_(p), and density ρ by thefollowing equation (with the units of m²S⁻¹:$\alpha = \frac{k}{\rho\quad c_{p}}$The higher the thermal diffusivity, the faster the heat is conductedthrough the material.

FIG. 43 illustrates a schematic diagram showing a grid 4300 of thesimulation results of heating each of cubes 4102 in the thermalprocessing simulation. As shown, center cube 4104 achieved the desiredthermal treatment of 3.0.

FIG. 44 illustrates a screen display 4400 showing exemplary heatsimulation for a 0.5 inch TPX carrier particle design. The TPX carrierparticle design has a thermal diffusivity value of 1.04*10⁻⁷ m²/s. TheTPX carrier particle design is heated for the same length of time underthe same conditions as carrier particle design 4100 (shown in FIG. 41).The holding time is set to 131.4 seconds.

FIG. 45 illustrates a schematic diagram showing a grid 4500 of theresult of heating the TPX carrier particle design of FIG. 44 in the samethermal processing simulation of the target particle. Square 4502 ofgrid 4500 can indicate the center of the TPX carrier particle design.The other squares of grid 4500 can indicate the result of the appliedthermal process simulation from square 4502 to the exterior of the TPXcarrier particle design. Line 4504 indicates dimensions for the interiorcavity of the carrier particle design suitable for a carrier particleabout matching the conservative behavior characteristics of thesimulated potato of FIGS. 41-43. Line 4504 can be conservatively placedto yield F₀ values of 3.0 or greater. Thus, a TPX carrier particledesign can be fabricated based on grid 4500. Grid 4500 indicates thatthe particle should have a wall thickness of about 2.54 mm. Thesimulation results show that the carrier particle design can match orexceed the conservative thermal characteristics of the simulated potato.

FIG. 46 illustrates a screen display 4600 showing exemplary heatsimulation for a 0.5 inch nylon carrier particle design. The nyloncarrier particle design has a thermal diffusivity value of 1.40*10⁻⁷m²/s. The nylon carrier particle design is heated for the same length oftime under the same conditions as carrier particle design 4100 (shown inFIG. 41). The holding time is set to 131.4 seconds.

FIG. 47 illustrates a schematic diagram showing a grid 4700 of theresult of heating the nylon carrier particle design of FIG. 46 in thesame thermal processing simulation of the target particle. Square 4702of grid 4700 can indicate the center of the nylon carrier particledesign. The other squares of grid 4700 can indicate the result of theapplied thermal process simulation from square 4702 to the exterior ofthe nylon carrier particle design. Line 4704 indicates dimensions forthe interior cavity of the carrier particle design suitable for acarrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 41-43. Thus, a nyloncarrier particle design can be fabricated based on grid 4700. Grid 4700indicates that the particle should have a wall thickness of about 4.45mm. The simulation results show that the carrier particle design canmatch or exceed the conservative thermal characteristics of thesimulated potato.

FIG. 48 illustrates a screen display 4800 showing exemplary simulationresults for a 0.5 inch TEFLON™ carrier particle design. TEFLON™ materialis available from E. I. Du Pont Demours and Company of Wilmington, Del.,United States of America. The TEFLON™ carrier particle design has athermal diffusivity value of 1.15*10⁻⁷ m²/s. The TEFLON™ carrierparticle design is heated for the same length of time under the sameconditions as carrier particle design 4100 (shown in FIG. 41). Theholding time is set to 131.4 seconds.

FIG. 49 illustrates a schematic diagram showing a grid 4900 of theresult of heating the TEFLON™ carrier particle design of FIG. 44 in thesame thermal processing simulation of the target particle. Square 4902of grid 4900 can indicate the center of the TEFLON™ carrier particledesign. The other squares of grid 4900 can indicate the result of theapplied thermal process simulation from square 4902 to the exterior ofthe TEFLON™ carrier particle design. Line 4904 indicates dimensions forthe interior cavity of the carrier particle design suitable for acarrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 41-43. Thus, a TEFLON™carrier particle design can be fabricated based on grid 4900. Thesimulation results show that the carrier particle design can match orexceed the conservative thermal characteristics of the simulated potato.

FIG. 50 illustrates a screen display 5000 showing exemplary simulationresults for a 0.5 inch polypropylene carrier particle design. Thepolypropylene carrier particle design has a thermal diffusivity value of1.15*10⁻⁷m²/s. The polypropylene carrier particle design is heated forthe same length of time under the same conditions as carrier particledesign 4100 (shown in FIG. 41). The holding time is set to 131.4seconds.

FIG. 51 illustrates a schematic diagram showing a grid 5100 of theresult of heating the polypropylene carrier particle design of FIG. 50in the same thermal processing simulation of the target particle. Square5102 of grid 5100 can indicate the center of the polypropylene carrierparticle design. The other squares of grid 5100 can indicate the resultof the applied thermal process simulation from square 5102 to theexterior of the polypropylene carrier particle design. Line 5104indicates dimensions for the interior cavity of the carrier particledesign suitable for a carrier particle about matching the conservativebehavior characteristics of the simulated potato of FIGS. 41-43. Thus, apolypropylene carrier particle design can be fabricated based on grid5100. The simulation results show that the carrier particle design canmatch or exceed the conservative thermal characteristics of thesimulated potato.

FIGS. 52-62 illustrate an exemplary procedure for simulating,calculating, and selecting carrier particle designs for carrying adetectable particle for monitoring and validation of thermal processingof a multiphase food material containing a ⅜ inch potato cube. FIG. 52illustrates a schematic diagram of a cubic particle design, generallydesignated 5200, for simulation by spatial simulation engine SSE. Cubicparticle design 5200 can be used to calculate the sequential lethality(F₀ value) increments during heating for a variety of materials. Cubicparticle design 5200 can be divided into smaller cubicles, generallydesignated 5202, including a cubicle 5204 at the center of particledesign 5200 and other cubicles extending to the exterior of cubicparticle design 5200. Cubic particle design 5200 can be used insimulating heating applied to the exterior of design 5200 and observingthe effect of the heating to cubicle 5204, the area of interest.

FIG. 53 illustrates a screen display 5300 showing exemplary heatsimulation results for cubic, potato particle design 5200 (shown in FIG.52) to an F₀ value of 3 minutes in the center. The required holding timeis about 82.1 seconds. In this simulation embodiment, target particledesign 4100 has a coefficient of thermal diffusivity of 1.63*10⁻⁷ m²/s.

FIG. 54 illustrates a schematic diagram showing a grid 5400 of theresult of heating each of cubes in the thermal processing simulation. Asshown, center cube 5402 achieved the desired F₀ treatment of 3.0minutes.

FIG. 55 illustrates a screen display 5500 showing exemplary simulationresults for a ⅜ inch TPX carrier particle design. The TPX carrierparticle design has a thermal diffusivity value of 1.04*10⁻⁷ m²/s. TheTPX carrier particle design is heated for the same length of time underthe same conditions as carrier particle design 5200 (shown in FIG. 52).The holding time is set to 82.1 seconds.

FIG. 56 illustrates a schematic diagram showing a grid 5600 of theresult of heating the TPX carrier particle design of FIG. 55 in the samethermal processing simulation of the target particle. Square 5602 ofgrid 5600 can indicate the center of the TPX carrier particle design.The other squares of grid 5600 can indicate the result of the appliedthermal process simulation from square 5602 to the exterior of the TPXcarrier particle design. Line 5604 indicates dimensions for the interiorcavity of the carrier particle design suitable for a carrier particleabout matching the conservative behavior characteristics of thesimulated potato of FIGS. 52-54. Thus, a TPX carrier particle design canbe fabricated based on grid 5600. The simulation results show that thecarrier particle design can match or exceed the conservative thermalcharacteristics of the simulated potato.

FIG. 57 illustrates a screen display 5700 showing exemplary heatsimulation for a ⅜ inch nylon carrier particle design. The nylon carrierparticle design has a thermal diffusivity value of 1.40*10⁻⁷ m²/s. Thenylon carrier particle design is heated for the same length of timeunder the same conditions as carrier particle design 5200 (shown in FIG.52). The holding time is set to 82.1 seconds.

FIG. 58 illustrates a schematic diagram showing a grid 5800 of theresult of heating the nylon carrier particle design of FIG. 57 in thesame thermal processing simulation of the target particle. Square 5802of grid 5800 can indicate the center of the nylon carrier particledesign. The other squares of grid 5800 can indicate the result of theapplied thermal process simulation from square 5802 to the exterior ofthe nylon carrier particle design. Line 5804 indicates dimensions forthe interior cavity of the carrier particle design suitable for acarrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 52-54. Thus, a nyloncarrier particle design can be fabricated based on grid 5800. Grid 5800indicates that the particle should have a wall thickness of about 3.84mm. The simulation results show that the carrier particle design canmatch or exceed the conservative thermal characteristics of thesimulated potato.

FIG. 59 illustrates a screen display 5900 showing exemplary simulationresults for a ⅜ inch TEFLON™ carrier particle design. The TEFLON™carrier particle design has a thermal diffusivity value of 1.15*10⁻⁷m²/s. The TEFLON™ carrier particle design is heated for the same lengthof time under the same conditions as carrier particle design 5200 (shownin FIG. 52). The holding time is set to 82.1 seconds.

FIG. 60 illustrates a schematic diagram showing a grid 6000 of theresult of heating the TEFLON™ carrier particle design of FIG. 59 in thesame thermal processing simulation of the target particle. Square 6002of grid 6000 can indicate the center of the TEFLON™ carrier particledesign. The other squares of grid 6000 can indicate the result of theapplied thermal process simulation from square 6002 to the exterior ofthe TEFLON™ carrier particle design. Line 6004 indicates dimensions forthe interior cavity of the carrier particle design suitable for acarrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 52-54. Thus, a TEFLON™carrier particle design can be fabricated based on grid 6000. Grid 4500indicates that the particle should have a wall thickness of about 1.92mm. The simulation results show that the carrier particle design canmatch or exceed the conservative thermal characteristics of thesimulated potato.

FIG. 61 illustrates a screen display 6100 showing exemplary simulationresults for a ⅜ inch polypropylene carrier particle design. Thepolypropylene carrier particle design has a thermal diffusivity value of1.15*10⁻⁷ m²/s. The polypropylene carrier particle design is heated forthe same length of time under the same conditions as carrier particledesign 5200 (shown in FIG. 52). The holding time is set to 82.1 seconds.

FIG. 62 illustrates a schematic diagram showing a grid 6200 of theresult of heating the polypropylene carrier particle design of FIG. 61in the same thermal processing simulation of the target particle. Square6202 of grid 6200 can indicate the center of the polypropylene carrierparticle design. The other squares of grid 6200 can indicate the resultof the applied thermal process simulation from square 6202 to theexterior of the polypropylene carrier particle design. Line 6204indicates dimensions for the interior cavity of the carrier particledesign suitable for a carrier particle about matching the conservativebehavior characteristics of the simulated potato of FIGS. 52-54. Thus, apolypropylene carrier particle design can be fabricated based on grid6200. The simulation results show that the carrier particle design canmatch or exceed the conservative thermal characteristics of thesimulated potato.

FIGS. 63-73 illustrate an exemplary procedure for simulating,calculating, and selecting carrier particle designs for carrying adetectable particle for monitoring and validation of thermal processingof a multiphase food material containing a 0.5 inch×0.5 inch,cylindrical potato. Referring specifically to FIG. 63, a schematicdiagram of a cylindrical particle design, generally designated 6300, forsimulation by spatial simulation engine SSE is illustrated. Cylindricalparticle design 6300 can be divided into smaller cylindrical portions,generally designated 6302. Cylindrical particle design 6300 can alsoinclude a cylinder 6304 at the center of portions 6302. In thisembodiment, design 6300 is divided into smaller cylindrical portions6302 for facilitating the simulation and observation of heating from theexterior of the cylinder to the center, the area of greatest interest.Cylindrical particle design 6300 can be used in simulating heatingapplied to the exterior of design 6300 and observing the effect of theheating to cylinder 6304, the area of interest.

FIG. 64 illustrates a screen display 6400 showing exemplary heatsimulation results for cylindrical particle design 6400 shown in FIG.63. The required holding time is about 120.5 seconds. In this simulationembodiment, target particle design 6300 has a coefficient of thermaldiffusivity of 1.63*10⁻⁷ m²/s.

FIG. 65 illustrates a schematic diagram showing a plurality of circularportions 6500 and the result of heating each of circular portions 6500in the thermal processing simulation. As shown, center circle 6502achieved the desired F₀ treatment of 3.0 minutes.

FIG. 66 illustrates a screen display 6600 showing exemplary simulationresults for a 0.5 inch TPX carrier particle design. The TPX carrierparticle design has a thermal diffusivity value of 1.04*10⁻⁷ m²/s. TheTPX carrier particle design is heated for the same length of time underthe same conditions as carrier particle design 6300 (shown in FIG. 63).The holding time is set to 120.5 seconds.

FIG. 67 illustrates a schematic diagram showing a plurality of circularportions 6700 of the result of heating the TPX carrier particle designof FIG. 66 in the same thermal processing simulation of the targetparticle. Center circle 6702 of portions 6700 can indicate the center ofthe TPX carrier particle design. The other circular portions of grid6700 can indicate the result of the applied thermal process simulationfrom center circle 6702 to the exterior of the TPX carrier particledesign. Line 6704 indicates dimensions for the interior cavity of thecarrier particle design suitable for a carrier particle about matchingthe conservative behavior characteristics of the simulated potato ofFIGS. 63-65. Thus, a TPX carrier particle design can be fabricated basedon portions 6700. The simulation results show that the carrier particledesign can match or exceed the conservative thermal characteristics ofthe simulated potato.

FIG. 68 illustrates a screen display 6800 showing exemplary simulationresults for a 0.5 inch nylon carrier particle design. The nylon carrierparticle design has a thermal diffusivity value of 1.40*10⁻⁷ m²/s. Thenylon carrier particle design is heated for the same length of timeunder the same conditions as carrier particle design 6300 (shown in FIG.63). The holding time is set to 120.5 seconds.

FIG. 69 illustrates a schematic diagram showing a plurality of circularportions 6900 of the result of heating the nylon carrier particle designof FIG. 46 in the same thermal processing simulation of the targetparticle. Circle 6902 of grid 6900 can indicate the center of the nyloncarrier particle design. The other squares of portions 6900 can indicatethe result of the applied thermal process simulation from circle 6902 tothe exterior of the nylon carrier particle design. Line 6904 indicatesdimensions for the interior cavity of the carrier particle designsuitable for a carrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 63-65. Thus, a nyloncarrier particle design can be fabricated based on grid 6900. Thesimulation results show that the carrier particle design can match orexceed the conservative thermal characteristics of the simulated potato.

FIG. 70 illustrates a screen display 7000 showing exemplary simulationresults for a 0.5 inch TEFLON™ carrier particle design. The TEFLON™carrier particle design has a thermal diffusivity value of 1.15*10⁻⁷m²/s. The TEFLON™ carrier particle design is heated for the same lengthof time under the same conditions as carrier particle design 6300 (shownin FIG. 63). The holding time is set to 120.5 seconds.

FIG. 71 illustrates a schematic diagram showing a plurality of circularportions 7100 of the result of heating the TEFLON™ carrier particledesign of FIG. 66 in the same thermal processing simulation of thetarget particle. Circle 7102 of portions 7100 can indicate the center ofthe TEFLON™ carrier particle design. The other circular portions of grid7100 can indicate the result of the applied thermal process simulationfrom circle 7102 to the exterior of the TEFLON™ carrier particle design.Line 4904 indicates dimensions for the interior cavity of the carrierparticle design suitable for a carrier particle about matching theconservative behavior characteristics of the simulated potato of FIGS.63-66. Thus, a TEFLON™ carrier particle design can be fabricated basedon circular portions 4900 . The simulation results show that the carrierparticle design can match or exceed the conservative thermalcharacteristics of the simulated potato.

FIG. 72 illustrates a screen display 7200 showing exemplary simulationresults for a 0.5 inch polypropylene carrier particle design. Thepolypropylene carrier particle design has a thermal diffusivity value of1.15*10⁻⁷ m²/s. The polypropylene carrier particle design is heated forthe same length of time under the same conditions as carrier particledesign 6300 (shown in FIG. 63). The holding time is set to 120.5seconds.

FIG. 73 illustrates a schematic diagram showing a plurality of circularportions 7300 of the result of heating the polypropylene carrierparticle design of FIG. 72 in the same thermal processing simulation ofthe target particle. Circle 7302 of circular portions 7300 can indicatethe center of the polypropylene carrier particle design. The othersquares of grid 7300 can indicate the result of the applied thermalprocess simulation from square 7302 to the exterior of the polypropylenecarrier particle design. Line 7304 indicates dimensions for the interiorcavity of the carrier particle design suitable for a carrier particleabout matching the conservative behavior characteristics of thesimulated potato of FIGS. 63-65. Thus, a polypropylene carrier particledesign can be fabricated based on grid 7300. The simulation results showthat the carrier particle design can match or exceed the conservativethermal characteristics of the simulated potato.

FIGS. 74-84 illustrate an exemplary procedure for simulating,calculating, and selecting carrier particle designs for carrying adetectable particle for monitoring and validation of thermal processingof a multiphase food material containing a ⅜ inch×⅜ inch, cylindricalpotato. FIG. 74 illustrates a schematic diagram of a cylindricalparticle design, generally designated 7400, for simulation by spatialsimulation engine SSE. Cylindrical particle design 7400 can be dividedinto smaller cylindrical portions, generally designated 7402, includinga cylinder 7404 at the center of particle design 7400 and othercylindrical shapes extending to the exterior of cylindrical particledesign 7400. Cylindrical particle design 7400 can be used in simulatingheating applied to the exterior of design 7400 and observing the effectof the heating to cylinder 7404, the area of interest.

FIG. 75 illustrates a screen display 7500 showing exemplary simulationresults for cylindrical particle design 7500 shown in FIG. 74. Therequired holding time is about 76.0 seconds. In this simulationembodiment, target particle design 6300 has a coefficient of thermaldiffusivity of 1.63*10⁻⁷ m²/s

FIG. 76 illustrates a schematic diagram showing a plurality of circularportions 7600 of the result of heating each of circular portions 7602 inthe thermal processing simulation. As shown, center circle 7604 achievedthe desired F₀ treatment of 3.0 minutes.

FIG. 77 illustrates a screen display 7700 showing exemplary simulationresults for a ⅜ inch TPX carrier particle design. The TPX carrierparticle design has a thermal diffusivity value of 1.04*10⁻⁷ m²/s. TheTPX carrier particle design is heated for the same length of time underthe same conditions as carrier particle design 7400 (shown in FIG. 74).The holding time is set to 82.1 seconds.

FIG. 78 illustrates a schematic diagram showing a plurality of circularportions 7800 of the result of heating the TPX carrier particle designof FIG. 77 in the same thermal processing simulation of the targetparticle. Circle 7802 of circular portions 7800 can indicate the centerof the TPX carrier particle design. The other circles of circularportions 7800 can indicate the result of the applied thermal processsimulation from circle 7802 to the exterior of the TPX carrier particledesign. Line 7804 indicates dimensions for the interior cavity of thecarrier particle design suitable for a carrier particle about matchingthe conservative behavior characteristics of the simulated potato ofFIGS. 52-54. Thus, a TPX carrier particle design can be fabricated basedon circular portions 7800. The simulation results show that the carrierparticle design can match or exceed the conservative thermalcharacteristics of the simulated potato.

FIG. 79 illustrates a screen display 7900 showing exemplary simulationresults for a ⅜ inch nylon carrier particle design. The nylon carrierparticle design has a thermal diffusivity value of 1.40*10⁻⁷ m²/s. Thenylon carrier particle design is heated for the same length of timeunder the same conditions as carrier particle design 7400 (shown in FIG.74). The holding time is set to 82.1 seconds.

FIG. 80 illustrates a schematic diagram showing a plurality of circularportions 8000 of the result of heating the nylon carrier particle designof FIG. 57 in the same thermal processing simulation of the targetparticle. Circle 8002 of portions 8000 can indicate the center of thenylon carrier particle design. The other squares of portions 8000 canindicate the result of the applied thermal process simulation fromsquare 8002 to the exterior of the nylon carrier particle design. Line8004 indicates dimensions for the interior cavity of the carrierparticle design suitable for a carrier particle about matching theconservative behavior characteristics of the simulated potato of FIGS.74-76. Thus, a nylon carrier particle design can be fabricated based ongrid 8000. The simulation results show that the carrier particle designcan match or exceed the conservative thermal characteristics of thesimulated potato.

FIG. 81 illustrates a screen display 8100 showing exemplary simulationresults for a ⅜ inch TEFLON™ carrier particle design. The TEFLON™carrier particle design has a thermal diffusivity value of 1.15*10⁻⁷m²/s. The TEFLON™ carrier particle design is heated for the same lengthof time under the same conditions as carrier particle design 7400 (shownin FIG. 74). The holding time is set to 76.0 seconds.

FIG. 82 illustrates a schematic diagram showing a grid 8200 of theresult of heating the TEFLON™ carrier particle design of FIG. 81 in thesame thermal processing simulation of the target particle. Circle 8202of grid 8200 can indicate the center of the TEFLON™ carrier particledesign. The other circles of grid 8200 can indicate the result of theapplied thermal process simulation from, circle 8202 to the exterior ofthe TEFLON™ carrier particle design. Line 8204 indicates dimensions forthe interior cavity of the carrier particle design suitable for acarrier particle about matching the conservative behaviorcharacteristics of the simulated potato of FIGS. 74-76. Thus, a TEFLON™carrier particle design can be fabricated based on grid 8200. Thesimulation results show that the carrier particle design can match orexceed the conservative thermal characteristics of the simulated potato.

FIG. 83 illustrates a screen display 8300 showing exemplary simulationresults for a ⅜ inch polypropylene carrier particle design. Thepolypropylene carrier particle design has a thermal diffusivity value of1.15*10⁻⁷ m²/s. The polypropylene carrier particle design is heated forthe same length of time under the same conditions as carrier particledesign 7400 (shown in FIG. 74). The holding time is set to 76.0 seconds.

FIG. 84 illustrates a schematic diagram showing a grid 8400 of theresult of heating the polypropylene carrier particle design of FIG. 83in the same thermal processing simulation of the target particle. Circle8402 of circular portions 8400 can indicate the center of thepolypropylene carrier particle design. The other circles of portions8400 can indicate the result of the applied thermal process simulationfrom circle 8402 to the exterior of the polypropylene carrier particledesign. Line 8404 indicates dimensions for the interior cavity of thecarrier particle design suitable for a carrier particle about matchingthe conservative behavior characteristics of the simulated potato ofFIGS. 74-76. Thus, a polypropylene carrier particle design can befabricated based on portions 8400. The simulation results show that thecarrier particle design can match or exceed the conservative thermalcharacteristics of the simulated potato.

The materials described herein for fabricating the carrier particle canhave a lower thermal diffusivity than the target particle material.Materials with lower thermal diffusivity require a thinner particle wallto achieve the same degree of thermal protection for the internalcarrier cavity. Nylon has a high thermal diffusivity value, and thusrequires a large wall thickness to provide the same level of thermalprotection as a material with a lower thermal diffusivity value.Polypropylene provides a high level of thermal protection, and thusrequires a thin wall thickness to provide the same level of thermalprotection as a material with a higher thermal diffusivity value.

The systems and methods described herein can provide a convenient toolfor flow and thermal process monitoring for other materials and othercriteria. By setting alternative (e.g., other than conservative)criteria for thermal property selections, a carrier particle can befabricated with representative characteristics (e.g., to mimic the realbehavior of present particles, rather than conservatively) or thermally“liberal” characteristics (i.e., to heat faster than the target materialunder identical conditions). Representatively designed carrier particlescan be used in fluid and multiphase dynamics studies while “liberally”designed particles can be used to evaluate the effect of respectivetreatments on quality characteristics and ingredients of materials.Under this scenario, the carrier particles thus represent the “mostthermally abused particle” rather than “least thermally processedparticle”. For quality studies, these particles can be of interest sincethe most abused particles typically define the quality threshold of aparticular food or biomaterial product (e.g., the one with the poorestflavor, color, or post-process retained bio-activity).

According to another embodiment, display D (shown in FIG. 13) candisplay images related to designing a carrier particle. User interfaceUI (shown in FIG. 13) can also receive user input related to designing acarrier particle. Memory MEM can include computer-readable instructionsfor receiving input from the operator, displaying images on display D,and providing information to spatial simulation engine (shown in FIG.13) for modeling a target and carrier particle and running thermalprocess simulations for the target and carrier particles as describedherein. One skilled in the art will appreciate that while these systemsand methods are useful for the design of carrier particles, they are notlimited by the use of the computer system CS (shown in FIG. 13). Thecarrier particles can also be designed without the use of the computersystem CS with the methodology described herein. Specifically, thecarrier particles can be designed, as described above, by building andthen heating particles of varying wall thicknesses under sameexperimental conditions as the food particle that is beingconservatively emulated. The particle design with the heatingcharacteristics most similar to the target food can then be selected asa desirable carrier particle. Experimental confirmation (underconcurrent heating) of the conservative nature for a simulated vs. realparticle will be employed regardless of which design basis isimplemented (i.e., software design vs. experimental design of multiplewall thickness increments). However, the software and systems describedherein can be advantageously used to computes the wall thicknessrequired for the minimally conservative design of a carrier particle aswell as other design parameters for the particle, thus providingartisans with a convenient and automatic tool for particle design.

One embodiment of methods, systems, and computer-readable instructionsdescribed herein is referred to as the “CPDesign” approach. The CPDesignapproach can integrate the sequential steps of particle design into onesingle application. Referring to FIG. 85, a flow chart, generallydesignated 8500, is shown which illustrates a process for designing acarrier particle having characteristics about matching the conservativebehavior characteristics of a selected target particle. The processbegins at the step indicated by reference numeral 8502. In step 8504,spatial simulation engine SSE (shown in FIG. 13) can simulate heating ofa target food particle until a target lethality is accumulated at thecold spot. Next, at step 8506, under similar conditions, a carrierparticle constructed of a suitable material can be simulated during thesame time period. At step 8508, the spatial lethality distributionwithin the polymer particle can be examined to determine the appropriate(minimally conservative) thickness of the wall between the interiorcavity for holding a detectable particle and the exterior of the carrierparticle.

Next, in step 8510, the weight of the detectable particle and any addedballast needed to achieve the target density of the carrier particle canbe calculated. The density of the carrier fluid can be determinedexperimentally or calculated based on the projected thermal history inthe hold tube (ρ_(fluid)). The maximum weight of the fabricated carrierparticle (containing all implant and any ballast materials) can becalculated assuming that the critical particle density is the same asthe carrier fluid (neutrally buoyant particle); or preferably slightlylower (by 0.5% or less) than the carrier fluid (a slightly buoyantparticle). This can be achieved by multiplying the volume of theselected target particle shape and size by the carrier fluid densityreduced by 0.5% or less. Therefore, the following equation results:W_(max) =V_(particle)*ρ_(fluid)*0.9995. Critical particle density is adensity which provides the highest likelihood that the particle can haveconservative (fast moving) flow particles.

From this maximum particle weight, maximum implant weight can becalculated by subtracting the weight of the thermally conservativecarrier particle shell from the maximum particle weight with thefollowing equation: W_(max-implant)=W_(max)−W_(carrier shell), whereinW_(carrier shell)=(V_(particle)*ρ_(fluid))−(V_(cavity*)ρ_(polymer)). Theweight of the carrier shell (or particle) can be calculated bysubtracting the weight of the polymer material removed in order tocreate a carrier cavity within the thermally conservative particle fromthe weigth of the particle having a target shape and dimensionsconstructed from a solid particle material. The polymer material for thefabrication of the carrier particle can be selected so that the maximumweight of the implants is maximized, i.e., in addition to theconservative properties of the carrier shell, density of the polymermaterial can be lower than the carrier fluid. This allows for themaximization of implant weight and subsequent easier detection orreading of traceable or recordable signals from the implants. Therefore,the total integrated maximum particle weight is given by the followingequation: W_(max) =W_(carrier shell)+W_(implant)+W_(ballast).

Referring to FIG. 85, the process can then stop at step 8512. Inparticular, heating of a target food particle can be simulated particleuntil a user-specified lethality is achieved at the center of particle.At the end of this first step, a heating time is determined to be usedin the simulation of the heating of a polymer material under identicalheating conditions. Then, by examining the spatial lethalitydistribution within the polymer particle, an appropriate wall thicknesscan be determined. By knowing the thermophysical properties, shape, andcharacteristic dimensions of the targeted food and the carrier particlematerial, and given known process variables (e.g., initial temperatureof particle, ambient temperature, fluid-to-particle heat transfercoefficient, and desired F₀ at the center of food particle) wallthickness of the polymer particle can be determined.

According to one embodiment, a CPDesign method warns the user if aconservative carrier particle design for the given polymer material andprocess variables is not possible. If this is the case, the user isprompted to either select a different polymer material or slightlyincrease the dimension of the polymer particle.

Calculation of the implant weight that can be placed inside the cavityis another important capability of the program, as it relates toconservative flow behavior of the carrier particle, which can beestablished in the process design.

In some embodiments, a CPDesign method can be used to monitor thermalprocessing of other materials based on other criteria by adjusting thedensity and dimension characteristics of the fabricated carrierparticle.

According to one embodiment, computer-readable instructions can be basedon the WINDOWS® operating system (available from Microsoft Corporationof Redmond, Wash., United States of America). Simulation results can besaved to memory MEM (shown in FIG. 13) and printed via a suitableprinter (not shown).

FIGS. 86-90B illustrate exemplary screen displays of the CPDesignapplication for a computer system (such as computer system CS shown inFIG. 13). Referring to FIG. 86, a screen display 8600 of the CPDesignapplication providing a dropdown menu 8602 for selecting a target foodparticle for simulation is illustrated. The target food particles forselection by menu 8602 can include potato, carrot, and any othersuitable food product.

Referring to FIG. 87, a screen display 8700 of the CPDesign applicationproviding a menu for receiving operator input for designing a carrierparticle. In this example, a potato is selected as the target foodparticle. Further, in this example, the carrier particle material isselected as TPX, and the carrier particle shape is selected ascylindrical. Screen display 8700 also shows characteristic informationfor a potato and TPX material, including density, thermal conductivity,and specific heat. The operator can also enter dimensions for thecylindrical-shaped carrier particle and cylindrical-shaped, potato,target particle. Additionally, the operator can enter an initialparticle temperature, ambient temperature, heat transfer coefficient,and desired F₀. The operator can also enter information regarding themaximum density of the target particle. After the operator enters thisinformation, computer system CS can determine the maximum weight of theimplant (i.e., combination of the detectable and carrier particles). Theresults of the simulation can be printed.

FIGS. 88A and 88B illustrate screen displays 8800 and 8802,respectively, of the CPDesign application providing the results of theinformation entered in screen display 8700 of FIG. 87. Referring to FIG.88B, line 8804 indicates the minimally conservative wall of acylindrical carrier particle having the entered information. In thisexample, the wall thickness is determined to be 2.67 millimeters.

FIGS. 89A and 89B illustrate screen displays 8900 and 8902,respectively, of the CPDesign application providing exemplary results ofother simulation information entered by an operator. In this example,the carrier particle has a cubical exterior and a spherical interiorcavity. Screen display 8902 includes line 8904 indicating the minimallyconservative wall of a cylindrical carrier particle having the enteredinformation. In this example, the wall thickness is determined to be1.91 millimeters.

FIGS. 90A and 90B illustrate screen displays 9000 and 9002,respectively, of the CPDesign application providing exemplary results ofother simulation information entered by an operator. In this example,the carrier particle has a cubical exterior and a spherical interiorcavity. Screen display 9002 includes line 9004 indicating the minimallyconservative wall of a cylindrical carrier particle having the enteredinformation. In this example, the wall thickness is determined to be1.91 millimeters.

It will be understood that various details of the presently disclosedsubject matter can be changed without departing from the scope of thepresently disclosed subject matter. Furthermore, the foregoingdescription is for the purpose of illustration only, and not for thepurpose of limitation.

1-43. (canceled)
 44. A device for generating a temperature measurementfor a batch or continuous stream of material, the device comprising: (a)a detectable particle comprising a signal that changes at apredetermined temperature; and (b) a carrier particle comprising aninterior cavity holding the detectable particle, wherein the carrierparticle comprises a conservative behavior characteristic matching atarget particle, wherein the thermal protection provided by the carrierparticle to the interior cavity is greater than or equivalent toconservative thermal behavior of a target particle at its cold spotunder similar heating conditions.
 45. The device of claim 44, whereinthe conservative behavior characteristics of the target particlecomprise conservative dimensional and thermal characteristics.
 46. Thedevice of claim 45, wherein the conservative dimensional characteristiccomprises a cube shape.
 47. The device of claim 45, wherein theconservative dimensional characteristic comprises a cylindrical shape.48. The device of claim 45, wherein the conservative thermalcharacteristic comprises a density between about 10 kg/M³ and 20,000kg/m³.
 49. The device of claim 44, wherein the carrier particlecomprises a material selected from the group consisting of polymer,biopolymer, and combinations thereof.
 50. The device of claim 44,wherein the carrier particle comprises polypropylene.
 51. The device ofclaim 44, wherein the carrier particle comprises methylpentene copolymer(TPX).
 52. The device of claim 44, wherein the carrier particlecomprises nylon.
 53. The device of claim 44, wherein the carrierparticle comprises a specific heat between about 122 J/(kg·° C.) and4,186 J/(kg·° C.).
 54. The device of claim 44, wherein the carrierparticle comprises a thickness between the interior cavity and anoutside surface of the carrier particle providing conservative thermalprotection to the interior cavity.
 55. A method of generating atemperature measurement for a batch or a continuous stream of material,the method comprising: (a) providing a device comprising: (i) adetectable particle comprising a signal that changes at a predeterminedtemperature; and (ii) a carrier particle comprising an interior cavityholding the detectable particle, wherein the carrier particle comprisesa conservative behavior characteristic matching a target particle,wherein the thermal protection provided by the carrier particle to theinterior cavity is greater than or equivalent to conservative behaviorcharacteristics of a target particle to the cold spot under similarheating conditions; (b) inserting the device provided in step (a) intothe batch or continuous stream; and (c) detecting a signal change of thedevice to thereby generate a temperature measurement for the batch orcontinuous stream.
 56. The method of claim 55, wherein the conservativebehavior characteristics of the target particle comprise conservativedimensional and thermal characteristics.
 57. The method of claim 56,wherein the conservative dimensional characteristic comprises a cubeshape.
 58. The method of claim 56, wherein the conservative dimensionalcharacteristic comprises a cylindrical shape.
 59. The method of claim56, wherein the conservative thermal characteristic comprises a densitybetween about 10 kg/m³ and 20,000 kg/m³.
 60. The method of claim 55,wherein the carrier particle comprises a material selected from thegroup consisting of polymer, biopolymer, and combinations thereof. 61.The method of claim 55, wherein the carrier particle comprisespolypropylene.
 62. The method of claim 55, wherein the carrier particlecomprises methylpentene copolymer (TPX).
 63. The method of claim 55,wherein the carrier particle comprises nylon.
 64. The method of claim55, wherein the carrier particle comprises a specific heat between about122 J/(kg·° C.) and 4,186 J/(kg·° C.).
 65. The method of claim 55,wherein the carrier particle comprises a thickness between the interiorcavity and an outside surface of the carrier particle providingconservative thermal protection to the interior cavity. 66-186.(canceled)